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Up Topic Rybka Support & Discussion / Rybka Discussion / A test for Rybka 3
- - By depamas Date 2009-10-16 05:06
8/7p/1p4pk/4K3/5PP1/2p3r1/4p3/2R5 w - - 0 1


White to Move and Win

The first move is  easy. But to find the way to the solution is very difficult...
Parent - By TedSummers (***) Date 2009-10-16 08:15 Edited 2009-10-16 08:29
From a slow Q9000@2GHz I get:

Analysis by Rybka 3:

1.Rh1+ Kg7
  -+  (-6.92)   Depth: 6   00:00:00  19kN

1.Ke4 c2
  -+  (-6.83)   Depth: 6   00:00:00  29kN
  -+  (-7.43)   Depth: 8   00:00:00  134kN

1.Rh1+ Kg7[]
  -+  (-7.25)   Depth: 8   00:00:01  169kN
  -+  (-7.97)   Depth: 10   00:00:03  843kN

1.Kf6
  -+  (-5.34)   Depth: 10   00:00:06  1426kN
  +-  (3.20 !)   Depth: 22   00:06:36  47965kN, tb=4924

Stockfish 1.5.1 finds the win much faster.

Analysis by Stockfish 1.5.1 64bit:

1.Kd4 Rf3 2.Rh1+ Kg7 3.Rc1 Rf1 4.Kd3 Rxc1 5.Kxe2 h5 6.gxh5 gxh5
  -+  (-5.93)   Depth: 6   00:00:01  12kN
  -+  (-10.74)   Depth: 10   00:00:01  415kN

1.Rh1+ Kg7 2.Ke4 c2 3.Rc1 b5 4.Kd4 Kf6 5.Rh1 b4 6.Rc1 b3 7.Kc4
  -+  (-8.20)   Depth: 10   00:00:01  455kN

1.Kf6 Rh3 2.Re1 c2 3.Rc1 b5 4.Re1 b4 5.f5 b3 6.fxg6 Rf3+ 7.Ke5 Kxg6
  -+  (-8.12)   Depth: 10   00:00:01  510kN
  -+  (-9.45)   Depth: 11   00:00:01  602kN

1.Rh1+ Kg7 2.Ke4 c2 3.Re1 Rc3 4.Rc1 b5 5.f5 Kf6 6.fxg6 hxg6 7.Kf4 g5+ 8.Ke4 b4 9.Kd4 e1Q 10.Rxe1 c1Q 11.Rxc1 Rxc1
  -+  (-8.32)   Depth: 11   00:00:01  684kN
  -+  (-8.92)   Depth: 13   00:00:02  1069kN

1.Kf6 Rh3 2.Ra1 Rh4 3.Rb1 Rh2 4.Kf7 Rh4 5.Kg8 Rh2 6.Re1 g5 7.f5 Rh4 8.Rxe2 Rxg4 9.Re7
  -+  (-7.79 !)   Depth: 13   00:00:02  1373kN
  +-  (4.24 !)   Depth: 31   00:01:13  329mN
Parent - - By Xaggard (**) Date 2009-10-16 08:22
8/7p/1p4pk/4K3/5PP1/2p3r1/4p3/2R5 w - - 0 1


Analysis by Protector 1.2.8 x64:

...
  (0.00)   20/32   00:00:00  383тП, tb=4
1.Kf6 Rh3 2.Ra1 Rh4 3.Rb1 Rh5 4.gxh5
  (0.50)   21/33   00:00:01  5166тП, tb=204
1.Kf6 Rh3 2.Ra1 Rh4 3.Rb1 Rh5 4.gxh5 Kxh5
  (0.80)   21/33   00:00:01  5166тП, tb=205
1.Kf6 Rh3 2.Ra1 Rh4 3.Rb1 Rh2 4.Kf7 c2
  (1.20)   21/33   00:00:01  5166тП, tb=206
1.Kf6 Rh3 2.Ra1 Rh4 3.Rb1 Rh2 4.Kf7 Rh5
  (1.70)   21/33   00:00:01  5166тП, tb=206
1.Kf6 Rh3 2.Ra1 Rh4 3.Rb1 Rh2 4.Kf7 Rh5
  (2.30)   21/33   00:00:01  5166тП, tb=206

Protector 1.2.8 x64 is the GREAT!!! It took him only one second to find out that black is lost here!
Parent - - By Xaggard (**) Date 2009-10-16 08:25
8/7p/1p4pk/4K3/5PP1/2p3r1/4p3/2R5 w - - 0 1


Analysis by Deep Shredder 12 x64:

...
1.Kf6 Rh3 2.Re1 c2 3.Kf7 Rh4 4.Kg8 g5 5.Rxe2 gxf4 6.Rxc2 Rxg4+ 7.Kh8 f3 8.Rb2 Kg6 9.Rxb6+ Kf5 10.Rb1 Rf4 11.Rb5+ Ke4
  (-3.41)   15/27   00:00:00  1544тП, bb=354
1.Kf6 Rh3 2.Re1 c2 3.Kf7 Rh4 4.Kg8 g5 5.f5 Rxg4 6.f6 Kg6 7.f7 Rf4 8.f8Q Rxf8+ 9.Kxf8 h5 10.Ke8 b5 11.Ke7 b4
  (-2.39)   16/36   00:00:00  1873тП, bb=766
1.Kf6 Rh3 2.Re1 c2 3.Kf7 Rh4 4.Kg8 g5 5.f5 Rxg4 6.f6 b5 7.f7 Rf4 8.f8Q+ Rxf8+ 9.Kxf8 g4 10.Kf7 g3 11.Kf6 g2 12.Ke5 b4
  (-1.99)   17/28   00:00:00  2183тП, bb=766
1.Kf6 Rh3 2.Re1 c2 3.Kf7 Rh4 4.Kg8 g5 5.f5 Rxg4 6.f6 b5 7.f7 Rf4 8.f8Q+ Rxf8+ 9.Kxf8 g4 10.Kf7 Kg5 11.Ke6 h5 12.Ke5 h4
  (-2.71)   18/31   00:00:01  2828тП, bb=766
1.Kf6 Rh3 2.Kf7 Rh4 3.Kf6 Rh2 4.Kf7 g5 5.f5 Rh4
  (-1.74)   19/43   00:00:02  7177тП, bb=1819
1.Kf6 Rh3 2.Ra1
  (5.15)   20/50   00:00:05  14530тП, bb=1819


Deep Shredder 12 x64 is also good. 5 seconds to find!
Parent - - By Xaggard (**) Date 2009-10-16 08:27
8/7p/1p4pk/4K3/5PP1/2p3r1/4p3/2R5 w - - 0 1


Analysis by Stockfish 1.5.1 64bit Intel:

...
1.Kf6 Rh3 2.Re1 Rh2 3.Ra1 Rh4 4.Re1 Rh2
  (0.00)   27   00:00:05  31473тП
1.Kf6 Rh3 2.Re1 c2 3.Ra1 Rh4 4.Re1 Rh2 5.Ra1 Rh4
  (0.00)   28   00:00:09  60579тП
1.Kf6 Rh3 2.Ra1 Rh4 3.Rb1 c2 4.Ra1 b5 5.Kf7 c1R 6.Rxc1 Rh3 7.Kg8 e1R 8.Rxe1
  (0.20 !)   29   00:00:16  106мП
1.Kf6
  (1.01 !)   30   00:00:22  152мП
1.Kf6 Rh3 2.Ra1 Rh4 3.Rc1 Rh3
  (4.24 !)   31   00:00:32  230мП


Stockfish 1.5.1 64bit Intel not so bad too.
Parent - By Xaggard (**) Date 2009-10-16 08:29
8/7p/1p4pk/4K3/5PP1/2p3r1/4p3/2R5 w - - 0 1


Analysis by Bright 0.4a:

...
1.Kf6 Rh3 2.Re1 c2 3.Kf7 Rh4 4.Kg8 g5 5.Rxe2 gxf4 6.Rxc2 Rxg4+ 7.Kf7 f3 8.Ke6 Rg2 9.Rc7
  (-3.12)   16/28   00:00:00  4721тП
1.Kf6 Rh3 2.Re1 c2 3.Kf7 Rh4 4.Kf8 g5 5.Rxe2 gxf4 6.Rxc2 Kg5 7.Rb2 f3 8.Kg7 Rxg4 9.Kxh7
  (-2.92)   17/35   00:00:01  6136тП
1.Kf6 Rh3 2.Ra1 Rh4 3.Re1 c2 4.Kf7 g5 5.Rxe2 gxf4 6.Rxc2 Kg5 7.Rf2 Kxg4 8.Ke6 Rh6+ 9.Kd5 f3 10.Ke5 Rh5+ 11.Kd4
  (-2.96)   18/35   00:00:01  8431тП
1.Kf6 Rh3 2.Ra1 Rh4 3.Re1 c2 4.Kf7 g5 5.Rxe2 gxf4 6.Rxc2 Kg5 7.Rf2 Kxg4 8.Rg2+ Kf3 9.Rb2 Rh6 10.Rb3+ Ke2 11.Ke7
  (-3.01)   19/41   00:00:01  13069тП
1.Kf6 Rh3 2.Ra1 Rh4 3.Re1 Rh2 4.Ra1 Rh4
  (0.00)   20/46   00:00:03  27010тП
1.Kf6 Rh3 2.Ra1 Rh4 3.Rb1 Rh5 4.Kf7 c2 5.Ra1 Rf5+ 6.gxf5 Kh5 7.f6 Kg4 8.f5 Kf3 9.fxg6 Kf2 10.gxh7 e1Q 11.Rxe1 Kxe1 12.h8Q c1Q 13.Qh1+ Kd2 14.Qxc1+ Kxc1
  (6.13)   21/53   00:00:06  53105тП

1.Kf6 Rh3 2.Ra1 Rh4 3.Rb1 Rh5 4.Kf7 c2 5.Ra1 Rf5+ 6.gxf5 Kh5 7.f6 Kg4 8.f5 g5 9.Ke8 Kf3 10.f7 Kf2 11.f8Q e1Q+ 12.Rxe1 Kxe1 13.Qe7+ Kd1 14.Qxg5 c1Q 15.Qxc1+ Kxc1
  (4.47)   22/53   00:00:08  75600тП

Exellent performance from Bright. 6 seconds!
Parent - By Xaggard (**) Date 2009-10-16 08:36
8/7p/1p4pk/4K3/5PP1/2p3r1/4p3/2R5 w - - 0 1


Analysis by Naum 4:

...
1.Kf6 Rh3 2.Re1 Rh2 3.Kf7 g5 4.f5 Rh4 5.Rxe2 Rxg4 6.f6 Rf4 7.Rh2+ Rh4 8.Rc2 g4 9.Rxc3 Rh5 10.Rc8 g3 11.Ke6 g2 12.f7 g1Q 13.f8Q+ Qg7 14.Qf4+
  (-0.27)   27/45   00:00:07  31139тП, tb=9342
1.Kf6 Rh3 2.Re1 Rh2 3.Rb1 Rh4 4.Re1 Rh2
  (0.00)   28/55   00:02:34  162мП, tb=402527
1.Kf6 Rh3 2.Re1 Rh2 3.Rb1 Rh4 4.Re1 Rh2
  (0.00)   29/37   00:02:35  166мП, tb=404799
1.Kf6 Rh3 2.Re1 Rh2 3.Rb1 Rh4 4.Re1 Rh2
  (0.00)   30/39   00:02:37  171мП, tb=408557
1.Kf6 Rh3 2.Re1 Rh2 3.Rb1 Rh4 4.Re1 Rh2
  (0.00)   31/40   00:02:41  179мП, tb=414132
1.Kf6 Rh3 2.Re1 Rh2 3.Rb1 Rh4 4.Re1 Rh2
  (0.00)   32/41   00:02:48  193мП, tb=425660
1.Kf6 Rh3 2.Re1 Rh2 3.Rb1 Rh4 4.Re1 Rh2
  (0.00)   33/41   00:03:03  216мП, tb=452498
1.Kf6 Rh3 2.Re1 Rh2 3.Rb1 Rh4 4.Re1 Rh2
  (0.00)   34/44   00:03:28  247мП, tb=505868


Naum 4 can't find the way even in 3.5 mins :(
Parent - - By George Tsavdaris (****) Date 2009-10-22 14:20

>Protector 1.2.8 x64 is the GREAT!!! It took him only one second to find out that black is lost here!


How many seconds it takes him to avoid 1.Ng5? or 1.Nxh4? here that loses and play 1.Nd4 that at least draws or even wins?

Note that Rybka 3 has many problems with this position to avoid 1.Ng5 while its clone engine finds it immediately.
And what about Rybka cluster? Can anyone(:-P Lukas) provide analysis for it? I guess it takes about 20-22 seconds to find.

3b1B2/1Ppb1NPq/r2p4/1p1KP2B/6Pr/nP1pkN2/4pnQ1/R3R3 w - - 0 1
Parent - By Geomusic (*****) Date 2009-10-23 06:30
this position has more activity than a bees nest :)
Parent - By Xaggard (**) Date 2009-10-23 09:04
Parent - By Xaggard (**) Date 2009-10-23 09:08
I don't know anything about Rybka 3 problems here but on my PC she finds that move in 27 seconds

3b1B2/1Ppb1NPq/r2p4/1p1KP2B/6Pr/nP1pkN2/4pnQ1/R3R3 w - - 0 1


Analysis by Rybka 3:

1.Nxh4
  +-  (2.98 !)   Depth: 6   00:00:00  50kN
1.Nxh4 Bc6+ 2.Ke6 Bxh4 3.g8Q
  +-  (2.99)   Depth: 6   00:00:00  51kN
1.Nxh4 Bxh4 2.g8Q Bc6+ 3.Ke6 Qxg8 4.b8Q Bxg2 5.Bh6+ Kd4 6.Qxg8 dxe5+ 7.Kd7 Ne4 8.Kxc7 Nc5 9.Qh7
  =  (0.00)   Depth: 7   00:00:01  243kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4 3.Rac1 c6+ 4.Rxc6 Bxc6+ 5.Nxc6 d2 6.Rxe2+ Kxe2 7.g8Q
  +/-  (0.82)   Depth: 7   00:00:02  379kN
1.N3g5 Bc6+ 2.Ke6 Bxg2 3.Nxh7 Bxb7 4.Nxd8 Bc8+ 5.Ke7 Nxg4
  +/-  (1.22)   Depth: 7   00:00:02  400kN
1.N3g5
  +-  (1.42 !)   Depth: 8   00:00:03  550kN
1.N3g5
  +-  (1.62 !)   Depth: 8   00:00:03  582kN
1.N3g5 Bc6+ 2.Ke6 Bxg2 3.Nxh7 Bxb7 4.Nxd8
  +-  (1.61)   Depth: 8   00:00:03  596kN
1.N3g5 Bc6+ 2.Ke6 Bxg2 3.Nxh7 Bxb7 4.Nxd8 Bc8+ 5.Ke7
  +-  (1.61)   Depth: 9   00:00:04  718kN
1.Nd4 Qe4+[]
  +/=  (0.32)   Depth: 10   00:00:27  5173kN
1.Nd4
  +/=  (0.52 !)   Depth: 11   00:00:33  6168kN
Parent - - By Dadi Jonsson (Silver) Date 2009-10-23 09:15

> Note that Rybka 3 has many problems with this position to avoid 1.Ng5 while its clone engine finds it immediately.


You clone-kiddies will see that it changes as (if?) more Rybka parts are added to your clone. Even after all those months of work that have gone into this effort there is still a lot missing from Rybka. Therefore you will see it behave differently in many positions. Also, since the cloners don't yet fully understand the code you will probably see strange changes in the program's behavior between versions (for example in positions where it behaves differently from Rybka).
Parent - - By Banned for Life (Gold) Date 2009-10-23 12:23
That's OK as long as they don't add the part that makes the engine forget about blind bishop endings...
Parent - - By Dadi Jonsson (Silver) Date 2009-10-23 16:35
You mention the blind bishop problem, indicating that it's fixed in the clone.

Now the question is if the blind bishop solution in the clone is a quick and dirty solution or a properly implemented improvement based on full understanding of the code. In the former case, it may be vulnerable to other/later changes in the code which may affect the blind bishop fix in unexpected ways. This would indicate that we are dealing with a clone. If, on the other hand, the cloners actually designed and wrote the code themselves from scratch, then the blind bishop solution they provide is likely to be stable and behave consistently between versions. The reason is simple: Programmers have a much better understanding of their own code than code originating from others.

Here is what I wrote in my previous post:

> ...since the cloners don't yet fully understand the code you will probably see strange changes in the program's behavior between versions (for example in positions where it behaves differently from Rybka).


I didn't expect anything of this kind to show up quickly, but... well, guess what? I got the following results from someone who has been testing the clone on various positions and thought it was rather funny in view of your post. Note that this is a 'blind bishop' position.

8/5k1p/8/6b1/2P1K3/8/8/8 b - - 0 74


The a-version, the older version of the clone, sees that it's a draw which is correct.

The d-version, the newer version of the clone, says that Black wins which is wrong.

This is based on approximately 5 minutes of analysis. It looks like the 'blind bishop' fix was implemented without full understanding of how the code works, so later changes broke it in this particular position.

I rest my case.
Parent - By Highendman (****) Date 2009-10-23 17:08
Perfect :)
Parent - - By Banned for Life (Gold) Date 2009-10-23 17:32
I think your "case" may rest on a weak foundation, but it depends on the differences between the a, b, and d variants of the mystery engine. My understanding is that differences between these versions are due to the people that are doing what they have to do to get them to build, rather than to the original (reverse engineering?) team. If my assumption is correct, it would indicate that the added knowledge for blind bishop might be prone to being jettisoned during the build process in the interest of expediency.

Getting back to your case, remember this is not a unique problem with reverse engineering efforts. You may recall that Rybka at one time had BB knowledge which got left out at in a later version.

The major disagreement that I would have with you would be over your assertion that the key is to understand the code. I see this as a means to an end with the really important aspect being the understanding of the underlying algorithms. If the mystery engine team is just cleaning up reverse engineered code, Vas will have nothing to worry about in the long term. On the other hand, if they are learning about underlying algorithmic differences with other engines and this knowledge goes out to the community and is actually used, there is a much bigger problem. But this is all based on my belief that Vas' advantage is that he has a better feel for the requisite algorithms, rather than that he is a better coder than anyone else.
Parent - - By Dadi Jonsson (Silver) Date 2009-10-23 18:52

> I think your "case" may rest on a weak foundation


Remember that I made a general statement that was in no way limited to the 'blind bishop' case. It just happened to be a perfect fit to what I had predicted.

> blind bishop might be prone to being jettisoned during the build process in the interest of expediency.


Was it jettisoned? My source specifically mentioned that he had found a case where it broke, so I thought he meant that there were other cases were it worked as before. If that is the correct, then your explanation of what happened breaks down.

> You may recall that Rybka at one time had BB knowledge which got left out at in a later version.


I doubt your theory that the 'blind bishop' fix was actually removed.

> The major disagreement that I would have with you would be over your assertion that the key is to understand the code. I see this as a means to an end with the really important aspect being the understanding of the underlying algorithms.


No disagreement here. You just chose to define 'understanding code' differently from me. I don't see how an author of an original chess program can get to the top of the scale without understanding the underlying algorithms. I certainly wouldn't suspect any of the current top authors of not understanding the underlying algorithms which their program is based on.
Parent - By Banned for Life (Gold) Date 2009-10-23 19:26
Was it jettisoned? My source specifically mentioned that he had found a case where it broke, so I thought he meant that there were other cases were it worked as before. If that is the correct, then your explanation of what happened breaks down.

If you want to show that it works in some cases and not others, you should show this with the same build. To the best of my knowledge, the a, b, and d variants are based on the same code baseline, but have been built differently by third parties. I don't understand why you would be overly concerned with the work of the third parties doing the windows compiles (the original authors seem to live exclusively in the Linux domain).

I doubt your theory that the 'blind bishop' fix was actually removed.

I didn't say it was removed from R3, I said it was left out. The reasoning is as follows:

BB worked in R2 and not in R3. Since BB isn't solved by any amount of search it seems reasonable to assume that there are specific rules that are applied to correct the otherwise erroneous evaluation. This fix was in R2 and not in R3.

You just chose to define 'understanding code' differently from me.

I start with the assumption that the Russian guys are very smart and talented, as well as ethically challenged. I further assume that the main reason there isn't more competition in the chess engine field is the lack of money, rather than a dearth of talent. My understanding is that the reverse engineering team used some parts of Rybka and not others, "borrowing" the other components from other places. Doing this and putting together a very strong engine requires some level of understanding, at least at the interfaces. I suspect that if they put the effort in, they will make good progress in understanding the underlying algorithms. At that point, if they are sufficiently motivated, they could write a spec and generate a clean implementation of the software. If Vas weren't pushing ahead with R4, this would probably be the fastest way to eclipse R3.
Parent - - By George Tsavdaris (****) Date 2009-10-23 17:57

>The a-version, the older version of the clone, sees that it's a draw which is correct.
>The d-version, the newer version of the clone, says that Black wins which is wrong.


I wonder where do you all find these a,b,d,e.... versions of the ????? engine.
I only see some source code in the ???? website, with version called x.xyxa(where x,y are digits) and not any a,b,d versions and definitely not any executables.
I guess you will not answer my question in public but it would be nice if you answered in private.

>This is based on approximately 5 minutes of analysis. It looks like the 'blind bishop' fix was implemented without full understanding of how >the code works, so later changes broke it in this particular position.


This is a wrong assumption since perhaps the original programmer(s) that reversed engineered(IF they did that) Rybka 3 and produced the original code of ???? engine, let's call it version a, are not the same with the programmers of version d. So perhaps the original programmers understood the code well, but the latter programmers that tried to improve the code introduced the bug(the fix of blind Bishop issue, to be vanished) because they didn't understand the code well.

Some indication also that the programmers that reversed engineered Rybka 3, actually understand the code of it are some examples of knowledge the ???? engine has, while Rybka 3 doesn't have.
For example in the following position the ???? engine immediately and from depth 6 understands the position as a draw, while Rybka 3 does not understand it at all showing a big advantage for white. Note that i had all endgame tablebases disabled of course.

8/8/1p3K2/p4p2/P7/4kp2/7R/8 w - - 0 1


Analysis by Rybka 3 1-cpu 32-bit:

84.Kf6xf5 f3-f2 85.Rh2-h1 Ke3-f3 86.Kf5-e5 Kf3-g2 87.Rh1-c1 Kg2-f3 88.Ke5-d5 Kf3-e2 89.Kd5-e4 Ke2-d2 90.Rc1-h1
  +-  (1.98)   Depth: 12   00:00:01  14kN
84.Kf6xf5
  +-  (2.18 !)   Depth: 13   00:00:01  22kN
84.Kf6xf5
  +-  (2.38 !)   Depth: 13   00:00:01  24kN
84.Kf6xf5
  +-  (2.78 !)   Depth: 13   00:00:02  28kN
84.Kf6xf5 f3-f2 85.Rh2-h1[] Ke3-f3 86.Kf5-e5[] Kf3-g2 87.Rh1-c1[] f2-f1Q 88.Rc1xf1[] Kg2xf1 89.Ke5-d5[]
  +-  (2.75)   Depth: 13   00:00:02  33kN
84.Kf6xf5 f3-f2 85.Rh2-h1[] Ke3-f3 86.Kf5-e5[] Kf3-g2 87.Rh1-c1[] f2-f1Q 88.Rc1xf1[] Kg2xf1 89.Ke5-d5[] Kf1-f2 90.Kd5-c6[] Kf2-e3 91.Kc6xb6[] Ke3-d4 92.Kb6xa5
  +-  (2.75)   Depth: 14   00:00:02  51kN
84.Kf6xf5 f3-f2 85.Rh2-h1 Ke3-e2 86.Kf5-e5 f2-f1Q 87.Rh1xf1 Ke2xf1[] 88.Ke5-d5 Kf1-f2
  +-  (2.29)   Depth: 15   00:00:05  221kN
84.Kf6xf5 f3-f2 85.Rh2-h1 Ke3-e2 86.Kf5-e5 f2-f1Q 87.Rh1xf1 Ke2xf1[] 88.Ke5-d5 Kf1-f2 89.Kd5-c4 Kf2-e3 90.Kc4-b5 Ke3-e4 91.Kb5xb6 Ke4-d5
  +-  (1.98)   Depth: 16   00:00:15  917kN
84.Kf6xf5 f3-f2 85.Rh2-h1[] Ke3-e2 86.Kf5-e5 f2-f1Q 87.Rh1xf1 Ke2xf1[] 88.Ke5-d5 Kf1-f2 89.Kd5-c4 Kf2-e3 90.Kc4-b5 Ke3-e4 91.Kb5xb6 Ke4-d5
  +-  (1.98)   Depth: 17   00:00:15  939kN
84.Kf6xf5 f3-f2 85.Rh2-h1[] Ke3-e2 86.Kf5-e5 f2-f1Q 87.Rh1xf1 Ke2xf1[] 88.Ke5-d5 Kf1-f2 89.Kd5-c4 Kf2-e3 90.Kc4-b5 Ke3-e4 91.Kb5xb6 Ke4-d5
  +-  (1.98)   Depth: 18   00:00:21  1437kN

Analysis by ?????:

84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-a7 Kc7-c6 95.a5-a6 Kc6-c7 96.Ka7-a8 Kc7-b6 97.a6-a7 Kb6-c7
  =  (0.05)   Depth: 14/29   00:00:00  129kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-a7 Kc7-c6 95.a5-a6 Kc6-c7 96.Ka7-a8 Kc7-b6 97.a6-a7 Kb6-c7
  =  (0.05)   Depth: 14/29   00:00:01  148kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-a7 Kc7-c6 95.a5-a6 Kc6-c7 96.Ka7-a8 Kc7-b6 97.a6-a7 Kb6-c7
  =  (0.05)   Depth: 15/29   00:00:01  159kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-a7 Kc7-c6 95.a5-a6 Kc6-c7 96.Ka7-a8 Kc7-b6 97.a6-a7 Kb6-c7
  =  (0.05)   Depth: 15/29   00:00:01  183kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8
  =  (0.05)   Depth: 16/31   00:00:01  214kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8
  =  (0.05)   Depth: 16/31   00:00:01  243kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8
  =  (0.05)   Depth: 17/31   00:00:01  285kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8
  =  (0.05)   Depth: 17/31   00:00:01  322kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.a5-a6 Ka8-b8
  =  (0.05)   Depth: 18/33   00:00:01  380kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.a5-a6 Ka8-b8
  =  (0.05)   Depth: 18/33   00:00:01  432kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.Kb2-c3 Ka8-b8
  =  (0.05)   Depth: 19/34   00:00:01  525kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.Kb2-c3 Ka8-b8
  =  (0.05)   Depth: 19/34   00:00:01  608kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.a5-a6 Ka8-b8 99.Kb2-a3 Kb8-a8
  =  (0.05)   Depth: 20/35   00:00:01  736kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.a5-a6 Ka8-b8 99.Kb2-a3 Kb8-a8
  =  (0.05)   Depth: 20/35   00:00:02  843kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.Kb2-a2 Ka8-b8 99.Ka2-a3 Kb8-c7
  =  (0.05)   Depth: 21/37   00:00:02  1057kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.Kb2-a2 Ka8-b8 99.Ka2-a3 Kb8-c7
  =  (0.05)   Depth: 21/37   00:00:02  1194kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.Kb2-a2 Ka8-b8 99.Ka2-a3 Kb8-c7 100.Ka3-b3 Kc7-b8
  =  (0.05)   Depth: 22/40   00:00:02  1453kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.Kb2-a2 Ka8-b8 99.Ka2-a3 Kb8-c7 100.Ka3-b3 Kc7-b8
  =  (0.05)   Depth: 22/40   00:00:02  1629kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.Kb2-a2 Ka8-b8 99.Ka2-a3 Kb8-c7 100.Ka3-b2 Kc7-d7 101.a5-a6 Kd7-c7
  =  (0.05)   Depth: 23/41   00:00:03  2053kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.Kb2-a2 Ka8-b8 99.Ka2-a3 Kb8-c7 100.Ka3-b2 Kc7-d7 101.a5-a6 Kd7-c7
  =  (0.05)   Depth: 23/41   00:00:03  2350kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.Kb2-a2 Ka8-b8 99.Ka2-a3 Kb8-c7 100.Ka3-b2 Kc7-d7 101.Kb2-a2 Kd7-c6
  =  (0.05)   Depth: 24/41   00:00:04  2960kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.Kb2-a2 Ka8-b8 99.Ka2-a3 Kb8-c7 100.Ka3-b2 Kc7-d7 101.Kb2-a2 Kd7-c6
  =  (0.05)   Depth: 24/41   00:00:04  3337kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.Kb2-a2 Ka8-b8 99.Ka2-a3 Kb8-c7 100.Ka3-b2 Kc7-d7 101.Kb2-a2 Kd7-c6 102.a5-a6 Kc6-c7
  =  (0.05)   Depth: 25/43   00:00:05  4117kN
84.Rh2-h5 f3-f2 85.Rh5xf5 Ke3-e2 86.Kf6-e5 f2-f1Q 87.Rf5xf1 Ke2xf1 88.Ke5-d5 Kf1-e2 89.Kd5-c6 Ke2-e3 90.Kc6xb6 Ke3-d4 91.Kb6xa5 Kd4-c5 92.Ka5-a6 Kc5-c6 93.a4-a5 Kc6-c7 94.Ka6-b5 Kc7-b8 95.Kb5-a4 Kb8-a8 96.Ka4-a3 Ka8-b8 97.Ka3-b2 Kb8-a8 98.Kb2-a2 Ka8-b8 99.Ka2-a3 Kb8-c7 100.Ka3-b2 Kc7-d7 101.Kb2-a2 Kd7-c6 102.a5-a6 Kc6-c7
  =  (0.05)   Depth: 25/46   00:00:05  4659kN
Parent - By Dadi Jonsson (Silver) Date 2009-10-23 18:52

> I wonder where do you all find these a,b,d,e.... versions of the ????? engine.


I don't have the engine.

> I guess you will not answer my question in public but it would be nice if you answered in private.


Of course it's no problem to answer in public. See above.

> This is a wrong assumption since perhaps


If it's just "perhaps", then how can you state that it's the wrong assumption? Did you mean "This is perhaps a wrong assumption since perhaps..." :)

Anyway, I'm out of here. Perhaps I'll have a closer look at your post later.
Parent - - By Lukas Cimiotti (Bronze) Date 2009-10-23 17:40
Are you really shure that Nd4 is best?

1.run:

3b1B2/1Ppb1NPq/r2p4/1p1KP2B/6Pr/nP1pkN2/4pnQ1/R3R3 w - - 0 1


Analysis by Rybka 3o92 cluster:

1.Nxh4 Nc2 2.Qg3+ Kd2 3.Rxe2+ dxe2 4.Nf3+ Kc3 5.Ne1+ Kd2 6.Nf3+ Kc3 7.Ne1+ Kd2 8.Nf3+ Kc3 9.Ne1+ Kd2 10.Nf3+ Kc3 11.Ne1+ Kd2 12.Nf3+ Kc3 13.Ne1+ Kd2 14.Nf3+ Kc3 15.Ne1+ Kd2 16.Nf3+
  =  (0.12 !)   Depth: 8   00:00:02  4840kN
1.Nxh4 Nc2 2.Qg3+ Kd2 3.Rxe2+ dxe2 4.Nf3+ Kc3 5.Ne1+ Kd2 6.Nf3+ Kc3 7.Ne1+ Kd2 8.Nf3+ Kc3 9.Ne1+ Kd2 10.Nf3+ Kc3 11.Ne1+ Kd2 12.Nf3+ Kc3 13.Ne1+ Kd2 14.Nf3+ Kc3 15.Ne1+ Kd2 16.Nf3+
  +/=  (0.27 !)   Depth: 8   00:00:02  4991kN
1.Nxh4 Nc2 2.Qg3+ Kd2 3.Rxe2+ dxe2 4.Nf3+ Kc3 5.Ne1+ Kd2 6.Nf3+ Kc3 7.Ne1+ Kd2 8.Nf3+ Kc3 9.Ne1+ Kd2 10.Nf3+ Kc3 11.Ne1+ Kd2 12.Nf3+ Kc3 13.Ne1+ Kd2 14.Nf3+ Kc3 15.Ne1+ Kd2 16.Nf3+
  +/=  (0.67 !)   Depth: 8   00:00:02  5338kN
1.Nxh4 Bxh4 2.g8Q Nc2 3.Bh6+ Qxh6 4.Qf3+ Kxf3 5.Nxh6 Ne3+ 6.Kd4 dxe5+ 7.Kc3 Nfd1+ 8.Raxd1 Nxd1+ 9.Kxd3 e4+ 10.Kd4 Bf6+
  +/-  (1.02)   Depth: 8   00:00:03  6027kN
1.Nxh4 Nc2 2.exd6 Bc6+ 3.Ke5 Bxg2 4.Nxg2+ Kd2 5.Nxd8 Rxd6 6.Bxd6 Qxg7+ 7.Ke6 Nd4+ 8.Kd5 cxd6 9.Nf7 Qf6 10.Ra2+ Kc3 11.Nf4 Qxf4 12.b8Q Qf3+ 13.Kxd6 Ne4+ 14.Kd7 Nc5+ 15.Kc8 d2 16.Qc7
  =  (0.00)   Depth: 9   00:00:07  16806kN
1.Nxh4 Nc2 2.Qf3+ Kd2[] 3.exd6 Bc6+ 4.Ke5[] Bxf3 5.Nxf3+ Ke3 6.N3g5 cxd6+ 7.Ke6 Nd4+ 8.Kd7
  =  (0.12 !)   Depth: 10   00:00:14  31348kN
1.Nxh4 Nc2 2.Qf3+ Kd2[] 3.exd6 Bc6+ 4.Ke5[] Bxf3 5.Nxf3+ Ke3 6.N3g5 cxd6+ 7.Ke6 Nd4+ 8.Kd7
  =  (0.12 !)   Depth: 10   00:00:18  37005kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4[] 3.Rac1 Nb1 4.exd6 Nf6+ 5.Ke5[] Rxh5+ 6.gxh5 cxd6+ 7.Nxd6 Ng4+ 8.Kd5 Nf6+ 9.Ke5 Ng4+ 10.Kd5 Nf6+ 11.Ke5 Ng4+ 12.Kd5 Nf6+ 13.Ke5 Ng4+ 14.Kd5 Nf6+ 15.Ke5 Ng4+ 16.Kd5
  =  (0.00)   Depth: 11   00:00:24  51703kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4[] 3.Rac1 c6+ 4.Nxc6 Nc4 5.bxc4 Bxc6+ 6.Ke6 Nc5+ 7.Kxd6[] Nxb7+ 8.Ke6 bxc4 9.g8Q Be4+ 10.Kd7 Bc6+ 11.Ke6 Be4+ 12.Kd7 Bc6+ 13.Ke6 Be4+ 14.Kd7 Bc6+ 15.Ke6 Be4+ 16.Kd7
  =  (0.00)   Depth: 12   00:00:37  79534kN
1.Nd4 Qe4+[] 2.Qxe4+ Nxe4[] 3.Rac1 c6+ 4.Nxc6 Nc4[] 5.bxc4 Bxc6+[] 6.Ke6 Nc5+[] 7.Kxd6[] Nxb7+[] 8.Ke6 Bf3+ 9.Nd6 Bxg4+ 10.Bxg4 Rxg4 11.cxb5 Rxd6+ 12.exd6 Bh4 13.Red1 d2 14.Rxd2 Nd8+ 15.Kd7 Kxd2 16.Ra1
  =/+  (-0.60)   Depth: 13   00:02:39  371mN, tb=1
1.Nxh4 Nc2 2.exd6 Bc6+ 3.Ke5 Bxg2 4.Nxg2+ Kf3 5.Nxd8[] Kxg2 6.Rg1+ Kh2 7.Rab1[] Rb6 8.Kf6 d2 9.Bg6[] Qh4+ 10.Kf7 d1Q 11.Rbxd1 Nxd1 12.dxc7 Qf6+ 13.Kg8 Kxg1 14.b8Q Rxb8 15.cxb8Q e1Q 16.Bxc2
  =  (-0.15)   Depth: 13   00:04:27  614mN, tb=1
1.Nxh4 Nc2 2.exd6 Bc6+ 3.Ke5 Bxg2 4.Nxg2+ Kf3 5.Nxd8[] Kxg2 6.Rg1+ Kh2 7.Rab1[] Rb6 8.Kf6 d2 9.Bg6[] Qh4+ 10.Kf7 d1Q 11.Rbxd1 Nxd1 12.dxc7 Qf6+ 13.Kg8 Kxg1 14.b8Q Rxb8 15.cxb8Q e1Q 16.Bxc2
  =  (-0.03 !)   Depth: 14   00:07:18  979mN, tb=1
1.Nxh4 Bxh4 2.g8Q Nc2 3.exd6 Nb4+ 4.Ke5 cxd6+ 5.Nxd6 Qxg8 6.Nf5+ Bxf5 7.Bc5+ Kd2 8.Bxb4+ Kc2 9.Rec1+ Kxb3 10.Rcb1+ Kc2 11.Rc1+ Kb3 12.Rcb1+ Kc2 13.Rc1+ Kb3 14.Rcb1+ Kc2 15.Rc1+ Kb3 16.Rcb1+
  =  (0.00)   Depth: 14   00:09:43  1305mN, tb=1
1.Nxh4 Bxh4 2.g8Q Nc2 3.exd6 Nb4+ 4.Ke5 cxd6+ 5.Nxd6 Qxg8 6.Nf5+ Bxf5[] 7.Bc5+ Kd2 8.Bxb4+ Kc2 9.Rec1+ Kxb3 10.Rcb1+ Kc2 11.Rc1+ Kb3[] 12.Rcb1+ Kc2 13.Rc1+ Kb3[] 14.Rcb1+ Kc2 15.Rc1+ Kb3[] 16.Rcb1+
  =  (0.00)   Depth: 15   00:11:46  1593mN, tb=2

2. run:

3b1B2/1Ppb1NPq/r2p4/1p1KP2B/6Pr/nP1pkN2/4pnQ1/R3R3 w - - 0 1


Analysis by Rybka 3o92 cluster:

1.Nd4 Qe4+ 2.Qxe4+ Nxe4 3.Rac1 Nb1 4.exd6 Nf6+ 5.Ke5 Rxh5+ 6.gxh5 cxd6+ 7.Nxd6 Ng4+ 8.Kd5 Nf6+ 9.Ke5 Ng4+ 10.Kd5 Nf6+ 11.Ke5 Ng4+ 12.Kd5 Nf6+ 13.Ke5 Ng4+ 14.Kd5 Nf6+ 15.Ke5 Ng4+ 16.Kd5
  =  (0.00)   Depth: 8   00:00:03  8677kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4 3.Rac1 Nb1 4.exd6 Nf6+ 5.Ke5 Rxh5+ 6.gxh5 cxd6+ 7.Nxd6 Ng4+ 8.Kd5 Nf6+ 9.Ke5 Ng4+ 10.Kd5 Nf6+ 11.Ke5 Ng4+ 12.Kd5 Nf6+ 13.Ke5 Ng4+ 14.Kd5 Nf6+ 15.Ke5 Ng4+ 16.Kd5
  =  (0.00)   Depth: 9   00:00:04  9376kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4 3.Rac1 Nb1 4.exd6 Nf6+ 5.Ke5 Rxh5+ 6.gxh5 cxd6+ 7.Nxd6 Ng4+ 8.Kd5 Nf6+ 9.Ke5 Ng4+ 10.Kd5 Nf6+ 11.Ke5 Ng4+ 12.Kd5 Nf6+ 13.Ke5 Ng4+ 14.Kd5 Nf6+ 15.Ke5 Ng4+ 16.Kd5
  =  (0.00)   Depth: 10   00:00:07  18244kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4 3.Rac1 Nb1 4.Nc2+ dxc2 5.Rxe2+ Kxe2 6.Kxe4 Nd2+ 7.Kf4 dxe5+ 8.Nxe5 Rf6+ 9.Kg3 Ne4+ 10.Kg2 Rf2+ 11.Kg1
  =  (0.12 !)   Depth: 11   00:00:14  34980kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4 3.Rac1 Nb1 4.Nc2+ dxc2 5.Rxe2+ Kxe2 6.Kxe4 Nd2+ 7.Kf4 dxe5+ 8.Nxe5 Rf6+ 9.Kg3 Ne4+ 10.Kg2
  +/=  (0.27 !)   Depth: 11   00:00:14  36306kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4 3.Rac1 Nb1 4.Nc2+ dxc2 5.Rxe2+ Kxe2 6.Kxe4 Nd2+ 7.Kf4 dxe5+ 8.Nxe5 Rf6+ 9.Kg3 Rf1 10.b8Q Rxc1 11.Qxd8 Rh3+ 12.Kxh3 Rh1+ 13.Kg2 c1Q
  =  (0.00)   Depth: 11   00:00:15  37266kN
1.Nxh4 Nc2 2.Qg3+ Kd2[] 3.Qf4+ Ne3+ 4.Qxe3+[] Kxe3[] 5.Nf5+ Qxf5 6.gxf5 Ne4 7.exd6 c6+
  =  (0.00)   Depth: 12   00:00:56  148mN
1.Nxh4 Nc2 2.exd6 Bc6+ 3.Ke5 Bxg2 4.Nxg2+ Kf3 5.Nxd8 cxd6+ 6.Ke6 Kxg2 7.Rg1+ Kh2 8.Rac1 d2 9.b8Q dxc1Q 10.Rxc1 Qh6+ 11.Kd7 Qxc1 12.Bxd6+ Kg1 13.Bh2+ Kh1 14.Qb7+ Kxh2 15.Qxa6 Ne4 16.Qg6
  =  (-0.20)   Depth: 13   00:02:11  369mN
1.Nxh4 Nc2 2.exd6 Bc6+ 3.Ke5[] Bxg2[] 4.Nxg2+ Kf3 5.Nxd8 cxd6+ 6.Ke6[] Kxg2 7.Rg1+ Kh2 8.Rab1 Rb6 9.Bxd6+ Kh3 10.Kf7
  =  (-0.08 !)   Depth: 14   00:03:38  571mN
1.Nxh4 Nc2 2.exd6 Bc6+ 3.Ke5[] Bxg2[] 4.Nxg2+ Kf3 5.Nxd8 Kxg2 6.Rg1+ Kh2 7.Rab1[] Rb6 8.Kf6 Na3 9.Rbe1 Nc2 10.Rb1 Na3 11.Rbe1 Nc2 12.Rb1 Na3 13.Rbe1 Nc2 14.Rb1 Na3 15.Rbe1 Nc2 16.Rb1
  =  (0.00)   Depth: 14   00:04:52  741mN
1.Nxh4 Nc2 2.exd6 Bc6+ 3.Ke5[] Bxg2[] 4.Nxg2+ Kf3 5.Nxd8 Kxg2 6.Rg1+ Kh2 7.Rab1[] Rb6 8.Kf6 Na3 9.Rbe1 Nc2 10.Rb1 Na3 11.Rbe1 Nc2 12.Rb1 Na3 13.Rbe1 Nc2 14.Rb1 Na3 15.Rbe1 Nc2 16.Rb1
  =  (0.00)   Depth: 15   00:06:05  955mN

(Cluster,  23.10.2009)

on a quad:
New game - Rybka 3w91 slave
3b1B2/1Ppb1NPq/r2p4/1p1KP2B/6Pr/nP1pkN2/4pnQ1/R3R3 w - - 0 1


Analysis by Rybka 3w91 slaveA:

1.N3g5 Bc6+ 2.Ke6 Bxg2 3.Nxh7 Bxb7 4.Nxd8 dxe5+ 5.Kd7 Bd5 6.Bc5+ Kf3 7.Ng5+ Kf4 8.Nge6+
  +/-  (0.90 !)   Depth: 6   00:00:00  14kN
1.N3g5 Bc6+ 2.Ke6 Bxg2 3.Nxh7 Bxb7 4.Nxd8 dxe5+ 5.Kd7 Bd5 6.Bc5+ Kf3 7.Ng5+ Kf4 8.Nge6+ Rxe6 9.Nxe6+ Bxe6+ 10.Kxe6
  +/-  (1.05 !)   Depth: 6   00:00:00  18kN
1.N3g5 Bc6+ 2.Ke6 Bxg2 3.Nxh7 Bxb7 4.Nxd8 dxe5+ 5.Kd7 Bd5 6.Bc5+ Kf3 7.Ng5+ Kf4 8.Nge6+ Rxe6 9.Nxe6+ Bxe6+ 10.Kxe6
  +-  (1.45 !)   Depth: 6   00:00:00  20kN
1.N3g5 Bc6+ 2.Ke6 Bxg2 3.Nxh7 Bxb7 4.Nxd8 dxe5+ 5.Kd7 Bd5 6.Bc5+ Kf3 7.Ng5+ Kg3 8.Nde6 Ra8 9.Bxa3 Nxg4 10.Rg1+ Bg2 11.Ne4+ Kh2 12.Nxc7 Rg8
  +-  (2.25 !)   Depth: 6   00:00:00  27kN
1.N3g5 Bc6+ 2.Ke6 Bxg2 3.Nxh7 Bxb7 4.Nxd8 dxe5+ 5.Kd7 Bd5 6.Bc5+ Kf3 7.Ng5+ Kg3 8.Nde6 Ra8 9.Bxa3 Nxg4 10.Rg1+ Bg2 11.Ne4+ Kh2 12.Nxc7 Rg8
  +-  (2.89)   Depth: 6   00:00:00  38kN
1.N3g5 Bc6+ 2.Ke6 Bxg2 3.Nxh7 Bxb7 4.Nxd8 dxe5+ 5.Kd7 Bd5 6.Bc5+ Kf3 7.Ng5+ Kg3 8.Nde6 Ra8 9.Bxa3 Nxg4 10.Rg1+ Bg2 11.Ne4+ Kh2 12.Nxc7 Rg8
  +-  (2.89)   Depth: 7   00:00:00  60kN
1.Nxh4 Nc2 2.Qg3+ Kd2 3.Qf4+ Ne3+ 4.Qxe3+ Kxe3 5.Nf5+ Qxf5 6.gxf5 Ne4 7.exd6 c6+
  =  (0.00)   Depth: 8   00:00:04  905kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4[] 3.Rac1 Nb1 4.exd6 Nf6+ 5.Ke5 Rxh5+ 6.gxh5 cxd6+ 7.Nxd6 Ng4+ 8.Kd5 Nf6+ 9.Ke5 Ng4+ 10.Kd5 Nf6+ 11.Ke5 Ng4+ 12.Kd5 Nf6+ 13.Ke5 Ng4+ 14.Kd5 Nf6+ 15.Ke5 Ng4+ 16.Kd5
  =  (0.00)   Depth: 9   00:00:07  1749kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4[] 3.Rac1 Nb1 4.Nc2+ dxc2 5.Rxe2+ Kxe2 6.Rxc2+ Kd3 7.Nxd8 Nec3+
  =  (0.12 !)   Depth: 10   00:00:09  2097kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4[] 3.Rac1 Nb1 4.Nc2+ dxc2 5.Rxe2+ Kxe2 6.Kxe4 Nd2+ 7.Kf4 Rh1 8.Rxc2 Rf1+ 9.Kg3 Rf3+ 10.Kg2 Rf2+ 11.Kh3 Rf3+ 12.Kh2 Rf2+ 13.Kh3 Rf3+ 14.Kh2 Rf2+ 15.Kh3 Rf3+ 16.Kh2
  =  (0.00)   Depth: 10   00:00:09  2133kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4[] 3.Rac1 Nb1 4.Nc2+ dxc2 5.Rxe2+ Kxe2 6.Kxe4 Nd2+ 7.Kf4 Rh1 8.Rxc2 Rf1+ 9.Kg3 Rf3+ 10.Kg2 Rf2+ 11.Kh3 Rf3+ 12.Kh2 Rf2+ 13.Kh3 Rf3+ 14.Kh2 Rf2+ 15.Kh3 Rf3+ 16.Kh2
  =  (0.00)   Depth: 11   00:00:19  4246kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4[] 3.Rac1 Nb1 4.Nf5+ Bxf5 5.gxf5 Nbc3+ 6.Rxc3[] Nxc3+ 7.Ke6 d2 8.Rxe2+ Nxe2 9.Bxe2 dxe5+ 10.Nd6 Kxe2 11.b8Q
  =  (0.12 !)   Depth: 12   00:00:45  10329kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4[] 3.Rac1 Nb1 4.Nf5+ Bxf5 5.gxf5 Nbc3+ 6.Rxc3[] Nxc3+ 7.Ke6 d2 8.Rxe2+ Nxe2 9.Bxe2 dxe5+ 10.Nd6 Kxe2 11.b8Q
  +/=  (0.27 !)   Depth: 12   00:00:51  11435kN
1.Nd4 Qe4+ 2.Qxe4+ Nxe4[] 3.Rac1 Nb1 4.Nf5+ Bxf5 5.gxf5 Nbc3+ 6.Rxc3[] Nxc3+ 7.Ke6 d2 8.Rxe2+ Nxe2 9.Bxe2 dxe5+ 10.Nd6 Kxe2 11.b8Q d1Q 12.Qxb5+ Kf2 13.Qxa6 Qxb3+ 14.Kd7 cxd6 15.Kxd8 e4 16.Qxd6
  =  (0.00)   Depth: 12   00:00:53  11794kN
1.Nd4 Qe4+[] 2.Qxe4+ Nxe4[] 3.Rac1 Nb1 4.Nf5+ Bxf5[] 5.gxf5 Nbc3+[] 6.Rxc3[] Nxc3+ 7.Ke6 d2 8.Rxe2+[] Nxe2 9.Bxe2 dxe5+ 10.Nd6 Kxe2 11.b8Q d1Q 12.Qxb5+[] Kf2 13.Qxa6[] Qxb3+[] 14.Kd7[] cxd6[] 15.Kxd8[] e4 16.Qxd6
  =  (0.00)   Depth: 13   00:01:47  24087kN, tb=20
1.Nxh4 Nc2 2.Qf3+ Kd2[] 3.exd6 Bf6 4.dxc7 Bc6+ 5.Ke6 Bxf3+ 6.Rxa6 Bxb7[] 7.Kxf6 Kxe1[] 8.Ng5 Nxg4+[] 9.Bxg4 Qxh4[] 10.Bxe2 dxe2 11.Kg6 Bxa6 12.Nf3+ Kd1 13.Nxh4 e1Q 14.g8Q Qg3+ 15.Kf7 Qxb3+ 16.Kg7
  =  (0.00)   Depth: 14   00:16:14  229mN, tb=210
Parent - - By ernest (****) Date 2009-10-29 22:53
Mystery engine likes Nxh4 immediately, with (0.00) eval after a few seconds...  :wink:
Parent - By yanquis1972 (****) Date 2009-10-30 00:55
hmmm, a certain other engine also wants to play nxh4 immediately and finds a 0.00 eval extremely quickly...

Analysis by Rybka 3:

1.Nxh4
  +-  (2.95)   Depth: 6   00:00:00  26kN
1.Nxh4 Bc6+ 2.Ke6 Bxh4 3.g8Q
  +-  (2.99)   Depth: 6   00:00:00  27kN
1.Nxh4 Bxh4 2.g8Q Bc6+ 3.Ke6 Qxg8 4.b8Q Bxg2 5.Bh6+ Kd4 6.Qxg8 dxe5+ 7.Kd7 Ne4 8.Kxc7 Nc5 9.Qh8
  =  (0.00)   Depth: 7   00:00:02  180kN
1.N3g5 Bxg5 2.Qg3+ Kd2 3.Nxg5 Rxg4 4.Qxg4
  +/-  (1.37)   Depth: 7   00:00:05  444kN
1.N3g5 Bc6+ 2.Ke6 Bxg2 3.Nxh7 Bxb7 4.Nxd8
  +-  (1.57)   Depth: 8   00:00:07  670kN
1.N3g5 Bc6+ 2.Ke6 Bxg2 3.Nxh7 Bxb7 4.Nxd8 Bc8+ 5.Ke7 Nxg4 6.g8Q Rxh5 7.Ne6 Bxe6 8.Kxe6 dxe5+
  +/-  (1.26)   Depth: 8   00:00:08  714kN
1.N3g5 Rxg4 2.Qf3+ Kd2 3.Rxe2+ dxe2 4.Qxe2+ Kxe2 5.Nxh7 Nc2 6.Bxg4+ Bxg4 7.Re1+ Kxe1 8.exd6 Bf3+ 9.Ke6 Bxb7 10.g8Q
  =  (-0.05)   Depth: 9   00:00:30  3102kN
1.Nxh4 Bxh4 2.g8Q Bc6+ 3.Ke6 Qxg8 4.b8Q Bxg2 5.Bh6+
  =  (0.00)   Depth: 9   00:00:35  3554kN
1.Nd4 Qe4+
  =  (0.22)   Depth: 9   00:00:37  3764kN
Parent - By Roland Rösler (****) Date 2009-10-30 02:50
This is the problem with the mystery engine. She likes it immediately or never!
Eyes wide open (not shut! :-)) is always better! I don´t like blinkers :-)

PS: To make a single strike isn´t great! To make more than 200 points every time is great!
PS2: We speak about bowling! :-)
Parent - - By Asylum (**) Date 2009-10-16 10:39
New game
8/7p/1p4pk/4K3/5PP1/2p3r1/4p3/2R5 w - - 0 1


Analysis by Fritz 12:

1.Ke4 c2 2.Rh1+ Kg7 3.f5 Rc3 4.Rc1 Kf6 5.Kf4 g5+ 6.Ke4 Rg3 7.Ra1 Rxg4+ 8.Kd3 Kxf5
  -+  (-8.38)   Depth: 11/23   00:00:00  165kN
1.Ke4 c2 2.Rh1+ Kg7 3.f5 Rc3 4.Rc1 Kf6 5.Kf4 g5+ 6.Ke4 Rg3 7.Ra1 Rxg4+ 8.Kd3 Kxf5
  -+  (-8.38)   Depth: 12/24   00:00:00  232kN
1.Ke4 c2 2.Rh1+ Kg7 3.f5 Rc3 4.Rc1 Kf6 5.Kf4 g5+ 6.Ke4 Rg3 7.Rh1 Rxg4+ 8.Kd3 Rf4 9.Kxc2 Kxf5
  -+  (-8.54)   Depth: 13/27   00:00:00  408kN
1.Ke4 c2 2.f5 Rb3 3.g5+ Kh5 4.Rh1+ Kg4 5.Rg1+ Rg3 6.Rc1 gxf5+ 7.Kd4 Kxg5 8.Rh1 Kf4 9.Rc1 h5 10.Ra1
  -+  (-13.16)   Depth: 14/32   00:00:01  3126kN
1.Kf6 Rh3 2.f5 c2 3.Ra1 b5 4.Re1 b4 5.Rc1 gxf5 6.g5+ Kh5 7.Kxf5 Rh4 8.Ra1 b3
  -+  (-10.85)   Depth: 14/32   00:00:01  3689kN
1.Kf6 Rh3 2.Kf7 b5 3.Ra1 Rh4 4.f5 c2 5.f6 Rxg4 6.Rh1+ Kg5 7.Kg7 Rc4 8.f7 c1Q 9.Rxc1 Rxc1
  -+  (-9.66)   Depth: 15/31   00:00:02  5805kN
1.Kf6 Rh3 2.Kf7 Rh4 3.Kg8 g5 4.f5 Rxg4 5.f6 Rf4 6.f7 g4 7.f8Q+ Rxf8+ 8.Kxf8 c2 9.Ke7 Kg5 10.Kd6 g3
  -+  (-6.57)   Depth: 16/36   00:00:03  8137kN
1.Kf6 Rh3 2.Kf7 Rh4 3.Kg8 g5 4.f5 Rxg4 5.f6 Rf4 6.f7 c2 7.f8Q+ Rxf8+ 8.Kxf8 Kg6 9.Ke7 Kf5 10.Kd6 Ke4 11.Ra1
  -+  (-5.98)   Depth: 17/31   00:00:03  8391kN
1.Kf6 Rh3 2.Kf7 Rh4 3.Kg8 g5 4.f5 Rxg4 5.f6 Rf4 6.f7 c2 7.f8Q+ Rxf8+ 8.Kxf8 g4 9.Ke7 Kg5 10.Kd6 Kf4 11.Kd5 g3
  -+  (-5.89)   Depth: 18/33   00:00:03  8639kN
1.Kf6 Rh3 2.Kf7 Rh4 3.Kg8 g5 4.f5 Rxg4 5.f6 Rf4 6.f7 c2 7.f8Q+ Rxf8+ 8.Kxf8 Kg6 9.Ke7 Kf5 10.Kd6 Ke4 11.Kc6 g4 12.Kxb6
  -+  (-5.43)   Depth: 19/32   00:00:03  9071kN
1.Kf6 Rh3 2.Kf7 Rh4 3.Kg8 g5 4.f5 Rxg4 5.f6 Rf4 6.f7 c2 7.f8Q+ Rxf8+ 8.Kxf8 Kg6 9.Ke7 Kf5 10.Kd6 Ke4 11.Kc6 g4 12.Re1 Ke3 13.Kxb6
  -+  (-5.77)   Depth: 20/35   00:00:03  9506kN
1.Kf6 Rh3 2.Kf7 Rh4 3.Kg8 g5 4.f5 Rxg4 5.f6 Rf4 6.f7 c2 7.f8Q+ Rxf8+ 8.Kxf8 Kg6 9.Ke7 Kf5 10.Kd6 Ke4 11.Rh1 g4 12.Re1 Kd4 13.Ra1
  -+  (-6.40)   Depth: 21/35   00:00:04  10508kN
1.Kf6 Rh3 2.Kf7 Rh4 3.Kg8 g5 4.f5 Rxg4 5.f6 Rf4 6.f7 c2 7.f8Q+ Rxf8+ 8.Kxf8 Kg6 9.Ke7 Kf5 10.Rh1 g4 11.Kd6 Ke4 12.Re1 Kd4 13.Kc6 g3 14.Kxb6
  -+  (-6.31)   Depth: 22/38   00:00:06  15734kN
1.Kf6 Rh3 2.Kf7 Rh4 3.Re1 c2 4.Kf6 Rh3 5.Ra1 e1Q 6.Rxe1 Rh2 7.Kf7
  -+  (-4.63)   Depth: 23/42   00:00:10  26504kN
1.Kf6 Rh3 2.Kf7 Rh4 3.Re1 g5 4.f5 Rxg4 5.Rxe2 Kh5 6.f6 Rc4 7.Rh2+ Kg4 8.Rc2 h5 9.Ke6 Re4+ 10.Kd5 Rf4 11.Ke6 h4 12.Rxc3 h3 13.Rc1
  -+  (-2.61)   Depth: 24/44   00:00:17  42741kN
1.Kf6 Rh3 2.Kf7 Rh4 3.Re1 g5 4.f5 Rxg4 5.Rxe2 Rc4 6.Rh2+ Rh4 7.Rc2 g4 8.Rxc3 Kg5 9.f6 Rh6 10.Rc6 g3 11.Rxb6 g2 12.Rb5+ Kg4 13.Rb4+ Kf3 14.Rb3+
  -+  (-2.61)   Depth: 25/45   00:00:20  48980kN

(16.10.2009)
Parent - By Bothkill (*) Date 2009-10-16 14:04
But Fritz 12 doesn't report it as a win for white. Still negative score.
- By Bothkill (*) Date 2009-10-16 07:37
Let's make it first a test for me:

1.Kf6 Rh3 ... then I can't figure how white can put pressure.

If 2.g5 then 2. ... Kh5 and the cage is open, no good I think...

Thinking... Depth 1/2 ply ... not making any progress ...

..seems I have to add some more chess knowledge!
- By depamas Date 2009-10-16 09:02
The solution is:

1.Kf6 Rh3 2.Ra1!
[‹2.Rb1 c2 3.Ra1 Rh4= ]

2...Rh4
[=2...Rh5 3.Kf7 g5 4.f5+-
=2...c2 3.Kf7+-
=2...b5 3.Kf7+-]

3.Rb1!
[‹3.Kf7 g5-+]

3...c2
[=3...b5 4.Ra1 b4 5.Kf7 b3 6.Kg8+- ]
=3...Rh3 4.Kf7 c2 5.Ra1+-]

4.Ra1

4...Rh3
[=4...b5 5.Kf7+- ]
=4...Rh2 5.Kf7+- ]

5.Kf7 g5 6.f5 Rh4 7.Kg8 Rxg4 8.Ra7+- Chessmate after this move

The last study of Joachim Iglesias.
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