ya
its from 6 men table base. correctly says mate in 524.

I am not surprised and I know that tablebases are wrong.
The question was not about tablebases but about engines so you should not give engines tablebases and maybe the engines can see the draw if they search 100 plies forward with no pruning(but I suggest not to wait for it to happen)

Uri

From what I understand, tablebases are pretty much just a hash of data in which every known position of a particular endgame has been predetermined. As far as I know, its the engine that has to take that information and use it according to the rules of chess.

I'd think in a properly coded engine, it would indeed (in this case), correctly identify a mate in 72, but when the 50th move is actually made, thats when the 50 rule move would actually kick in.

Engines make a move, then go through a checklist to see if the move causes a known "flag" in programming parley in which the game would end: draw by lack of material, draw by repetition, draw from 50 move rule, checkmate, stalemate, clock flag down (for either or both sides), etc.

You also have to understand that tablebases mearly report the longest possible mate given perfect play from a given position. Engines aren't written to assume best play: in fact, after each move they pretty much look at the board as if it was new. Sure they have deep thinking, and can keep thousands of individual lines in a hash table (ram) in order to cut down on searching, but once they move or the opponent moves, its like they never really played that last move. They look at the hash table and say something to the effect "OMG look at all these cool lines I don't have to recalculate.. sweet.. I'll just start searching lines not in the hash table."

you mean nobody is allowed to find bad mistakes in "old" posts (especially yours...)? 

I think you were confused by Generated by Aquarium phrase. Only the nice output was produced by Aquarium, but the endgame was generated by special software.

Yes, you are right, Black's moves are incorrect in several cases. It's a mistake when producing the line, I will fix and recalculate it - maybe in a couple of days. Thank you for the report.

But the initial value seems to be right - 545 moves until checkmate.

Here is a new line (I have fixed the output).

There was the problem that output procedure ignored conversions to minor endgames.

Are your tables in Nalimov format? If no are they larger than Nalimov ones? And what's the size of table with 545 moves mate? Thank you!