Critter bug - known or unknown?

[Justin Sherron]

First of all, thanks to Richard for sharing Critter! I very much enjoy its style and strength.

But I am curious if it's a known bug that using the "Clear Hash" button with Arena causes Critter 0.80's castling ability to malfunction in regular chess games? The program sends the move Ke8xh8 (or Ke8xa8) when trying to castle as black, or produces an empty PV line when trying to castle as white. The problem is reproducible and persists until the engine is restarted.

Sorry if this is already known. I read Richard mentioned potential castling problems in Arena when he first announced the engine, but I had the impression he was specifically referring to Chess960, and I don't know if this is related or not.

(As a side note, I noticed unusual behavior when testing in Aquarium as well. Actually I never saw a successful castling in Aquarium before the program stopped and timed out, regardless of clearing the hash or not. Is this unusual or expected? Critter seems to like the Fritz GUI much better on my system.)

[rvida]

Hi,

thank you for reporting this. It is indeed a bug in Critter's UCI parser. If the GUI does not set the "UCI_Chess960" option at all then everything is working. As soon as the GUI sets this option (even if it sets it to "false") Critter erroneously always switches to FRC mode.

However I am not able to fix this at the moment, because I am on holidays until end of August.

Richard

Edit: P.S. This has nothing to do with clearing hash in arena, rather than with pressing the OK button afterwards.

[Justin Sherron]

Edit: P.S. This has nothing to do with clearing hash in arena, rather than with pressing the OK button afterwards.

Hehe, whoops. But I was only one button click away from being correct though. That's pretty close, right?