TalkChess.com

[JonP01]

I came across this interesting position in one of my machine versus machine games. Once this position was reached, I waited for what I thought would be the obvious winning move - Rc2 (there are clearly a few other "correct" moves as well where the King covers b1, but Rc2 is the one I would have played).

I was very surprised when white infact played Rxe6?? This move pretty much converts a completely won position to an extremely difficult win at best and perhaps nothing more than a draw (the game was infact drawn). When, after the game I put the position through HIARCS to verify I was not missing something, the evaluation went instantly from 5.83 in favour of white to only 1.43 in favour of white after Rxe6??

I then tried this position on my most powerful dedicated (Novag Amber) and it too plays Rxe6 even on it's longest tournament level. And even on analysis, it still wasn't budging from Rxe6.

I then tried the Mephisto Roma emulation on my Palm (which runs 3 times the speed of the original Roma) and it too could not find anything better than Rxe6 - even after 6 minutes thought. For those who don't know, Roma was the last top of the line Mephisto that did not have hash tables.

Contrast this to Chess Genius on the same Palm machine (with 200 Mhz xscale processor) and it found one of several correct continuations after only 25 seconds. But of course Chess Genius has a very fast processor and hash tables - 2Mb worth of them. It would have been interesting to see what it thought without hash tables, but they can't be disabled.

Anyway, I am curious to see if there is any dedicated chess machine in existence that does not have endgame hash tables and can find one of the correct continuations in this position within a reasonable time frame (by that I mean the maximum time it might take in a tournament game - perhaps ten minutes or less)? I wonder if such a machine exists? And of course, I would be interested to know how long it takes models with hash tables as well. I wonder, for example, can machines like Novag Diamond / Sapphire or StarDiamond find this on their 40 move in 2 hour tournament levels?


[D]5k2/8/1PR1p1p1/3p3p/8/1K4P1/7P/5r2 w - - 0 50