Is the Nolot Test Suite irrelevant?

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Topic Rybka Support & Discussion / Rybka Discussion / Is the Nolot Test Suite irrelevant?

By apollox (***)

Date 2009-05-20 10:13

I have been searching the Rybka topics for a summary of how Rybka has performed against the Nolot Test Suite. It is mentioned in the IDeA section of the Aquarium help, but I can't seem to find a just a general round-up of how Rybka and/or IDeA have fared in all the tests. People have talked about it, but none too recently.

All I was looking for was a general overview of how Rybka compares with other engines for these tests. Does anyone have that info?

By Werewolf (*****)

Date 2009-05-20 10:22

Yes. I use parts of the Nolot suite in composing my own test suites.
The bottom line is this: Some of the Nolot positions are too easy for programs now. Other positions are still useful. Rybka's tactical strength exceeds that of any other program and hence it performs better than the rest in such positions.

By apollox (***)

Date 2009-05-20 10:41

Thanks for answering quickly. Cool.

So what's the lowdown for each of the tests for Rybka in the order that Wiki has them http://en.wikipedia.org/wiki/Nolot ?

I guess just a simple judgement scale will do such as EASY - MEDIUM - HARD - VERY HARD

eg.
1. EASY
2. MEDIUM etc.

By Permanent Brain (*****)

Date 2009-05-20 11:09 Edited 2009-05-20 11:19

I don't think that the performance of just one engine is sufficient to determine the (general) difficulty of a test position, except for that engine specifically.

As a test suite intended to get useful overall results from, the Nolot test in itself is certainly much too small.

By GCP

Date 2009-05-20 11:12

I saw in some places Nolot 3 isn't solved, but Deep Sjeng can solve it in 20 mins on a quad.

I can get the score over +2 in Nolot 9 but on a different move, so maybe the solution is wrong or not unique.

In general test suites don't mean much.

By BB

Date 2009-05-21 03:58

I thought the Nolot test died out a decade ago, but here's some history:

http://www.exeterchessclub.org.uk/Trawl/ComputerProb.html
http://web.archive.org/web/20040403210216/brucemo.com/compchess/nolot/index.htm
http://web.archive.org/web/20040420021422/brucemo.com/compchess/nolot/nolot2.txt [the links on the above page don't work]
http://web.archive.org/web/20040420021422/brucemo.com/compchess/nolot/nolot3.txt

For position #3, Hsu said:

r2qk2r/ppp1b1pp/2n1p3/3pP1n1/3P2b1/2PB1NN1/PP4PP/R1BQK2R w KQkq -

Smaguine - Sahovic, Bienne 1990: White wins with a queen sac but black has several ways to defend

>12.Nxg5!! Bxd1 13.Nxe6 Qb8 14.Nxg7!! Kf8 15.Bh6! Bg4 16.0-0+ 17.Kg8 17.Rf4 +-
>It should take between a few months and a few years for a program to find 12.Nxg5!!

We took a closer look at this position. 12. Ng5 is a sound positional sac, but depending on the temperament of the player, it might not be the best move. The published annotation gives 12. Bg5 Bg5 13. o-o as +=, but white could play 13. h3 instead and white appears to have a simple positional squeeze. The critical line in the 12. Ng5 variation turns out to be 12. Ng5 Bd1 13. Ne6 Qb8 14. Ng7 Kd8 15. Kd1. Black's queen and rooks are temporarily out of play, black is up a pawn, but white has a protected passed pawn, and lots of pressure. (The annotator gave one line that ended "with the attack":). From DT-2's point of view, The Bg5 line was gaining 0.20 pawn after each iteration, and so was the Ng5 line. Except that the Bg5 line has about a 0.20 pawn lead at the same depth. There appears to be no kill in the Ng5 line when black king goes to d8 instead of the f file. Black would have to give up the extra pawn to activate the queen and the rooks, and while white is definitely better, black is not without counter play. On the deepest search that we checked out, black's evaluation stopped dropping at around -1.4 pawns, and black's pieces were becoming active.

For position 9, Hsu simply says: It is not clear to us either whether 1. Ng5!? actually works.

r4r1k/4bppb/2n1p2p/p1n1P3/1p1p1BNP/3P1NP1/qP2QPB1/2RR2K1 w - - 0 0

By nine castles (**)

Date 2009-05-21 05:06

A couple years back I ran the then-strongest engines Junior 9 and Shredder 9 on these positions. I remember that after days of thinking on #9, Junior would play Nf6 which transposes into the key line. The position is ludicrously complex so it's unlikely that anyone will be able to prove it rigorously, but I think the key probably does work.

#3 is the one where I have never seen anything substantiating the key move as the best, and it seems that Hsu's analysis is basically right, though I haven't seen what Rybka thinks about it. I know she solves #1 and a couple others very fast, but I never did go through them all. If Deep Sjeng plays the key after 20 minutes that is very interesting and I would like to see what its PV is.

By GCP

Date 2009-05-21 15:54

Seems to be taking ages for the fail high to resolve. So I can't see a definite PV yet. Score is >= 0.80.

All time seems to be spent in this variation:
Nxg5 Bxd1 Nxe6 Qb8 Nxg7+ Kf8 Bh6 Bg4 O-O+ Kg8 Rf4 Bc8 Raf1 Nxe5 dxe5

If I get a PV back before my patience expires, I'll post it.

By GCP

Date 2009-05-21 16:29

Ok I'm not patient enough. Score for Nxg5 gets +1.5 or more in all lines. Bxg5 seems to be mostly harmless, more around +0.3.

1.Nxg5!!
[1.Bxg5? Bxg5 2.h3 (2.O-O Qe7 3.Qe1 Bxf3 4.Rxf3 O-O-O) 2...Bxf3 3.Qxf3 =]
1...Bxd1 2.Nxe6 Qc8 3.Nxg7+ Kd8
[3...Kf8? 4.Bh6 Bg4 5.O-O+ Kg8 6.N3f5! (6.Rf4 Bg5 7.Bxg5 Kxg7 8.Nf5+ Bxf5 9.Bxf5 Qb8
10.Bf6+ Kf7 11.Raf1) 6...Bf8 7.Rf4 Bxf5 8.Bxf5 Bxg7 9.Rg4 Qxf5 10.Rxg7+ Kf8 11.Rg5+]
[3...Kf7 4.Bh6]
4.Bf5 Qb8 5.Kxd1 Na5 6.Ne6+ Kd7 7.Nf4+ Kc6 8.Be6 Bg5 9.Bxd5+ Kb6 10.Kc2
[10.b4 Nc6 11.Bc4 Ne7 12.d5 Bxf4 13.Bxf4 Nxd5 14.Bxd5 Rd8 15.c4 c6 16.Be3+]
10...Bxf4 11.Bxf4 Qd8 12.Be4 Qh4 13.Raf1 Raf8 14.Bf5

By Dragon Mist (****)

Date 2009-05-23 00:39

R3 seems to be pretty fast on this position, though. Sees Nxg5! in below 200 secs, and on my slow laptop. Here are the results from my laptop (Core2Duo @ 2 Ghz, 512 MB hash):

By Dragon Mist (****)

Date 2009-05-23 00:42

Fail high at d16 resolved at +1.48, failing high at d17 further. Sorry, only now I saw that apollox already did R3 on this one.

By Dragon Mist (****)

Date 2009-05-23 00:46

And guess who is way faster then R3?! R3Dynamic, of course. :-)

By Vasik Rajlich (Silver)

Date 2009-05-23 06:02

With that kind of score, maybe this position really is valid. (I always had some doubts about it.)

Vas

By ernest

Date 2009-05-24 00:25 Edited 2009-05-24 00:28

Here is the status of the Nolot suite, according to the author himself (Pierre Nolot is a friend).

The solutions of the 11 positions of the suite are valid, except for 2.

Position 6
Malaniuk - Ivanchuk, Moscow 1988 key ... axb5!!

rnbqk2r/1p3ppp/p7/1NpPp3/QPP1P1n1/P4N2/4KbPP/R1B2B1R b kq - bm axb5; id "

Position 6";

13... axb5!! 14.Qxa8 Bd4 15.Nxd4 and Black wins
BUT if White plays 15.Ra2 → Draw

Position 9
Weinstein - Elyoseph, Israel 1992 key ... Ng5!!

r4r1k/4bppb/2n1p2p/p1n1P3/1p1p1BNP/3P1NP1/qP2QPB1/2RR2K1 w - - bm Ng5; id "

Position 9";

1.Ng5!! hxg5 2.hxg5! Rac8 3.Nf6!!   and White wins
BUT if Black plays 2... Rfc8   → Draw

Note: today's programs prefer 1.Nxh6 !   which seems better (but probably not winning)

By Roland Rösler (****)

Date 2009-05-24 02:00

Thanks!

>The solutions of the 11 positions of the suite are valid, except for 2.

What´s valid here. Move wins ... or only this move wins?

PS: Let us see ... We speak again in 10 years! :-)

By Uri Blass (*****)

Date 2009-05-24 06:23

I disagree with you about position 6.
There is nothing bad in drawing move when other moves are worse than draw and in position number 6 white has the advantage if black does not play axb5

By apollox (***)

Date 2009-05-23 19:35

Nolot #9 is a problem.

There's something wrong with Ng5 which is suggested as the winning move according to Nolot. Nf6 is played immediately by Rybka. I am not sure if Ng5 as the first move can ever work.

By apollox (***)

Date 2009-05-21 07:27

Thanks. This is what I was looking for! How did you find this? I must have passed over this when I googled.

It gives a complete run down on all the tests. Although this page was last updated in 2002, it gives a pretty fair summary about how things were at that time.

What I see coming out of this seems to be the progression of engine development over the past 15 years. It is good that it remained as a yardstick over this period so we can see how our 'ancestors' perceived the problems.

They are good problems in that they are actual games resulting from practical play and not composed puzzles. This is not to denigrate the efforts of those who create chess problems, but actual positions arising from matches make them interesting.

By nine castles (**)

Date 2009-05-20 11:21

Last I heard there are still some doubts that the key move is the best move in every position. Also, in Position 5 - Spassky-Petrosian: while the key is without question the best move from an objective standpoint, white has a choice of winning plans, and so it's not a big deal if an engine does not find the key, so long as it finds another winning move.

By apollox (***)

Date 2009-05-21 10:49 Edited 2009-05-21 10:59

I decided to run #3 for a while just to see what Rybka thinks.

Rybka likes Nxg5 of course and by the time it reached D19 the evaluation was still increasing steadily.

I can't conclude a win on Rybka's 1.74 at the point I stopped; I usually consider it more certainly a done deal for Rybka at around 2.50 or so. But 1.74 is a pretty hefty advantage just the same in Rybka terms. It's a good hunt to watch though. Think I'll play it out vs. HIARCS :)

By Vasik Rajlich (Silver)

Date 2009-05-21 05:23

I think the best way to handle Nolot is to have the engines play the positions.

In some cases there are multiple good moves, and in others you can stumble into the supposed solution.

Vas

By plicocf (***)

Date 2009-05-21 16:05

I don´t agree. A test position it´s not a game. In some positions
of Nolot Rybka will win almost all.

By Vasik Rajlich (Silver)

Date 2009-05-22 04:56

> In some positions of Nolot Rybka will win almost all.

Which is the point. :)

Vas

By plicocf (***)

Date 2009-05-22 16:04

Point? I have no point, because now I understand what you wrote. =)
But now I have a point: Better than putting two engines to play,
would be the analysis of strong freestyles players or strong
correspondence chess players.

By Vasik Rajlich (Silver)

Date 2009-05-23 06:03

Right, but you need a way to "score" the quality of analysis.

Vas

By Jonas

Date 2009-05-24 04:37

..and rybka eval on deep analysis isnt a good score?

i guess to be really sure we have to solve chess first.. btw would you hurry up with that?

By nine castles (**)

Date 2009-05-24 17:32

The whole point of this suite is to test the ability of the engines, so it would be circular if we validated the engine performance via the fact that they agree with their own analysis.

By apollox (***)

Date 2009-05-25 10:59

Thanks to the contributions in this post I can surmise with confidence that the Nolot tests are soundly beaten. There are some ambiguities with nos. 3, 6, and 9 - but these are matters mostly of evaluation scoring. For that matter, all the tests but for a couple seem to have as their main basis for any interest is evaluation comparisons. But we can do that with any given position - can't we?
The forum is loaded with exotic positions from actual match games which are far more rich in possibilities for the Rybka family and other engines to chew on.

On the side of positive opinion for the tests, Nolot is an important curiosity in that it shows the gigantic leap within 20 years that chess computer science has hurdled.

Some mention must go to Hsu's Deep Thought. Although it was defeated with little trouble by Kasparov, it remains the first serious attempt of a computer to challenge the human champion. That in itself it is a remarkable achievement when you think about it.

They were busy creating tomorrow in the 1980s...

By turbojuice1122 (Gold)

Date 2012-04-03 11:11

I have finally checked all of these with IDeA running Rybka 4.1, and they are all confirmed except for Number 9, which is simply wrong. Also, I didn't actually input the winning lines at any point, though in a couple of instances, I kept having it suggest more alternatives later down in the analysis until it found the correct lines. The only situation in which I did this on the original move was with Number 9, which is wrong anyway.

Number 1: [fen]

r3qb1k/1b4p1/p2pr2p/3n4/Pnp1N1N1/6RP/1B3PP1/1B1QR1K1 w - -

[/fen]
It doesn't take IDeA long to get this one correct: 1.Nxh6 is the only move with a positive score, and it is at +2.38.

Number 2: [fen]

r4rk1/pp1n1p1p/1nqP2p1/2b1P1B1/4NQ2/1B3P2/PP2K2P/2R5 w - -

[/fen]
Same here: 1.Rxc5 is the only move with a positive score, and this ends up at +5.50.

Number 3: [fen]

r2qk2r/ppp1b1pp/2n1p3/3pP1n1/3P2b1/2PB1NN1/PP4PP/R1BQK2R w KQkq -

[/fen]
This one proved surprisingly easy with IDeA, though I remember it is difficult with infinite analysis, partly because other moves give a positive score. However, IDeA eventually has 1.Nxg5!! as the only move that is clearly winning, with a score of +1.75.

Number 4: [fen]

r1b1kb1r/1p1n1ppp/p2ppn2/6BB/2qNP3/2N5/PPP2PPP/R2Q1RK1 w kq -

[/fen]
1.Nxe6! is the only move that clearly wins, and IDeA gives a score of +1.55.

Number 5: [fen]

r2qrb1k/1p1b2p1/p2ppn1p/8/3NP3/1BN5/PPP3QP/1K3RR1 w - -

[/fen]
This one is fairly easy, and is possibly not the only winning move. My score is +5.50 for 1.e5, though 1.Nce2 gives +1.27 early without much further analysis.

Number 6: [fen]

rnbqk2r/1p3ppp/p7/1NpPp3/QPP1P1n1/P4N2/4KbPP/R1B2B1R b kq -

[/fen]
This one is very difficult--I had to tempt it with finding alternatives to get better lines in the later analysis before it would give this a decent score, but the best that black seems to be able to do here is get a draw, though with a better position. My line goes 1...axb5! 2.Qxa8 Bd4 3.Rb1 Qc7 4. bxc5 Bxc5 5. Rxb5 Na6 6. h3 Nf6 7. Be3 Nxe4 8. Bxc5 Naxc5 9. Qa5 Qd6 10. Rb6 {-0.48} (10. Nd2 {-0.48} 10... O-O 11. Nxe4 {-0.48} (11. Rg1 {-0.48} 11... Nxd2 {-0.48} (11... Qf6 {-0.48} 12. Nxe4 Nxe4 {R} {-0.48} )12. Qxd2 Bd7 13. Rb4 {-0.48} )11... Nxe4 12. Rg1 Qf6 13. Qe1 {-0.48} )(10. Rg1 {-0.48} 10... O-O 11. Nd2 {R} {-0.48} ) 10... Qe7 {-0.48} (10... Qd8 {-0.48} 11. Rb5 Qd6 {R} {-0.48} ) 11. Ke1 Nd7 12. Rb1 Ng3 13. Rg1 {-0.48} *

Number 7: [fen]

1r1bk2r/2R2ppp/p3p3/1b2P2q/4QP2/4N3/1B4PP/3R2K1 w k -

[/fen]
This one is very easy. 1.Rxd8 is the only positive scoring move, and it gives +3.25.

Number 8: [fen]

r3rbk1/ppq2ppp/2b1pB2/8/6Q1/1P1B3P/P1P2PP1/R2R2K1 w - -

[/fen]
This one is easy to find, but I don't think that this wins--the best that I've been able to get is a draw with an easier position for white after 1.Bxh7!. My analysis goes 1. Bxh7+ Kxh7 2. Qh5+ Kg8 3. Rd4 Bf3 4. gxf3 Qxc2 5. Rd7 Qg6+ 6. Qxg6 fxg6 7. Be5 Re7 8. Rad1 Kf7 9. Kg2 Rae8 10. R7d4 b6 11. Rf4+ {+0.80} (11. h4 {+0.80} 11... Rb7 12. R1d3 Bc5 {+0.80} ) 11... Kg8 12. Rg4 Kh7 13. Rgd4 {+0.80} (13. Rh4+ {+0.80} 13... Kg8 14. Rg4 {R} {+0.80} ) 13... Rb7 14. f4 Bc5 {+0.80} *

Number 9: [fen]

r4r1k/4bppb/2n1p2p/p1n1P3/1p1p1BNP/3P1NP1/qP2QPB1/2RR2K1 w - -

[/fen]
As is known by now, the key is wrong here: 1.Nxg5?! gives white only a draw after 1. Ng5 hxg5 2. hxg5 Rfc8 3. Nf6 gxf6 4. gxf6 Nxd3 5. Rxd3 Bxd3 6. Qxd3 Nxe5 7. Rxc8+ Rxc8 8. Bxe5 Qa1+ 9. Bf1 Bf8
However, white actually has a win that is easy to find: 1. Nxh6! Bg6 {+1.91} (1... gxh6 {+1.91} 2. Bxh6 Qb3 3. Rxc5 Bxc5 4. Ng5 Bg6 5. Bxc6 {+1.91} (5. h5 {+1.91} 5... Bf5 6. Bxc6 {+1.91} )5... Rac8 {+1.91} ) (1... Rac8 {+1.91} 2. Rxc5 Bxc5 3. Ng5 Bg6 4. Nhxf7+ Bxf7 {R} {+1.91} )(1...Na4 {+1.91} 2. Nd2 Rac8 3. Bxc6 Nc5 {+1.91} ) 2. Nxf7+ Bxf7 {+1.91} (2...Rxf7 {+1.91} 3. Ng5 Rxf4 4. gxf4 Rc8 5. h5 Bf5 6. Nf7+ Kh7 {+1.91} (6... Kg8 {+1.91} 7. Nd6 {+1.91} )7. Nd6 Bxd6 {+1.91} ) 3. Rxc5 Bxc5 4. Ng5 g6 {+1.91} (4... Rac8 {+1.91} 5. Bxc6 g6 {R} {+1.91} ) 5. Bxc6 Rac8 6. Bb5 Qd5 {+1.91} *

Number 10: [fen]

r1b2rk1/1p1nbppp/pq1p4/3B4/P2NP3/2N1p3/1PP3PP/R2Q1R1K w - -

[/fen]
1. Rxf7! is easy to find early and is the only winning move with a score of +2.38.

Number 11: [fen]

r1b3k1/p2p1nP1/2pqr1Rp/1p2p2P/2B1PnQ1/1P6/P1PP4/1K4R1 w - -

[/fen]
The move 1.Rxh6! is easy to find, but it only draws. Here is my analysis on this:

1. Rxh6 Nxh6 2. Qg5 Nf7 3. Qd8+ Nxd8 4. h6 Qd4 5. h7+ Kf7 6. g8=Q+ Ke7 7. h8=Q
{+0.00} (7. Rg7+ {+0.00} 7... Kd6 8. h8=Q {R} {+0.00} ) 7... Kd6 8. Rg7 Qxd2
{+0.00} (8... Nf7 {+0.00} 9. Rxf7 {+0.00} (9. Qxf7 {+0.00} 9... Qxd2 10.
Be2 {+0.00} (10. Qxc8 {+0.00} )10... b4 {+0.00} )(9. Qxc8 {+0.00} 9... Rxc8
{+0.00} (9... Nxh8 {+0.00} )10. Qxc8 {+0.00} )9... Qxd2 10. Qf8+ {+0.00}
(10. Bxb5 {R} {+0.00} ) (10. Rxf4 {+0.00} 10... Qd1+ 11. Kb2 Qd4+ {+0.00} )
(10. Qd8 {+0.00} 10... Qd1+ 11. Kb2 {+0.00} ) (10. Bxe6 {+0.00} 10... Qd1+
{+0.00} )(10. Qxc8 {+0.00} )10... Kc7 11. Qd8+ {+0.00} (11. Bxe6 {+0.00}
11... Qe1+ {+0.00} (11... Qd1+ {+0.00} )12. Kb2 {+0.00} )(11. Rxf4 {+0.00}
11... Qd1+ {+0.00} )11... Kb7 12. Bxe6 Qe1+ {+0.00} (12... Qd1+ {+0.00} )) 9.
Bxb5 {+0.00} (9. Qf8+ {+0.00} 9... Kc7 10. Qxd8+ Kb7 11. Bxe6 Nxe6 {+0.00}
(11... Qe1+ {+0.00} 12. Kb2 Nd3+ 13. cxd3 Qf2+ {+0.00} )(11... Qd1+ {+0.00}
12. Kb2 Qd4+ {+0.00} (12... Nd3+ {+0.00} )13. Kb1 Qd1+ {R} {+0.00} )12. Qe7
{+0.00} (12. Qf6 {+0.00} 12... Qd1+ {+0.00} (12... Nd4 {+0.00} )(12... Nxg7
{+0.00} )13. Kb2 Qd4+ 14. Kc1 {+0.00} ) (12. Qdh4 {+0.00} 12... Nxg7 {+0.00}
(12... Qd1+ {+0.00} )) (12. Qdg8 {+0.00} 12... Nxg7 {+0.00} (12... Qd1+
{+0.00} ))(12. Qde8 {+0.00} 12... Nd4 {+0.00} (12... b4 {+0.00} ) (12...
Qd1+ {+0.00} )(12... Nxg7 {+0.00} ))12... Qd1+ 13. Kb2 Qd4+ 14. Kc1 Qa1+ 15.
Kd2 Qd4+ 16. Kc1 {R} {+0.00} )(9. Qxd8 {+0.00} 9... Qd1+ 10. Kb2 Qd4+ 11. Kc1
{+0.00} (11. c3 {+0.00} 11... Qd2+ 12. Kb1 Qe1+ {+0.00} (12... Re8 {+0.00}
) (12... Qd1+ {+0.00} ) (12... Ng6 {+0.00} )(12... Kc5 {+0.00} )13. Kb2 Qd2+
{R} {+0.00} ) (11. Ka3 {+0.00} 11... Qc5+ 12. b4 {+0.00} (12. Kb2 {+0.00}
12... Qd4+ {R} {+0.00} )12... Qe3+ {+0.00} )(11. Kb1 {+0.00} 11... Qd1+ {R}
{+0.00} )11... Kc5 {+0.00} (11... Qa1+ {+0.00} 12. Kd2 Kc5 {+0.00} (12...
Qd4+ {+0.00} )13. Bxe6 {+0.00} )12. Kb1 {+0.00} (12. Qhf8+ {+0.00} 12... Rd6
{+0.00} (12... d6 {+0.00} ))12... Ng6 {+0.00} (12... Qd1+ {+0.00} )) 9...
Qd1+ {+0.00} (9... Bb7 {+0.00} 10. Qxd8 Rxd8 {+0.00} (10... Qd1+ {R} {+0.00}
)11. Qxd8 Bc8 {+0.00} (11... Qd1+ {+0.00} 12. Kb2 Qd4+ {+0.00} )12. Qxc8
{+0.00} (12. Ba6 {+0.00} 12... Kc5 {+0.00} )(12. Bc4 {+0.00} )12... Qd1+
{+0.00} ) (9... Nf7 {+0.00} 10. Rxf7 Qd1+ {R} {+0.00} (10... cxb5 {+0.00} ))
(9... cxb5 {+0.00} 10. Qxd8 Qd1+ {+0.00} ) (9... Kc5 {+0.00} 10. Bc4 {+0.00}
)(9... Qe1+ {+0.00} ) 10. Kb2 Qd4+ {+0.00} (10... Nf7 {+0.00} 11. Qxf7
{+0.00} (11. Rxf7 {R} {+0.00} )11... Qd4+ {+0.00} (11... Kc7 {+0.00} )12.
Kb1 {R} {+0.00} (12. Ka3 {+0.00} )) (10... Bb7 {+0.00} 11. Qxd8 {R} {+0.00}
) (10... cxb5 {+0.00} 11. Qxd8 {+0.00} )(10... Ng6 {+0.00} ) 11. Kb1 Nf7
{+0.00} (11... Qd1+ {R} {+0.00} ) (11... Kc5 {+0.00} 12. Qxd8 {+0.00} (12.
Bc4 {+0.00} )12... Qd1+ {+0.00} (12... Kxb5 {+0.00} )) (11... Bb7 {+0.00}
12. Qxd8 Rxd8 {+0.00} (12... Qd1+ {+0.00} 13. Kb2 Qd4+ {+0.00} (13... Rxd8
{+0.00} )14. Kb1 {R} {+0.00} (14. Ka3 {+0.00} )))(11... cxb5 {+0.00} ) 12.
Rxf7 {+0.00} (12. Qxf7 {+0.00} 12... Qd1+ {+0.00} (12... cxb5 {+0.00} ))
12... Qd1+ {+0.00} (12... Bb7 {+0.00} )(12... cxb5 {+0.00} ) 13. Kb2 Qd4+
{+0.00} *

Topic Rybka Support & Discussion / Rybka Discussion / Is the Nolot Test Suite irrelevant?