Monday, October 10, 2011

Komodo3 Engine Warning!

DO NOT USE THIS ENGINE!!


As I pointed out in a previous post, the evaluation function of this engine is suspect.  Take a look at this position, Black to play:
:

It's obvious that White stands better and Houdini 1.5 x64 recommends 1...Qc7 with White's advantage at about 1/3 of a Pawn.  Wanting to check this with another engine, I set up the position and left Komodo3 ponder it while I went off to do something else. 5-1/2 hours later I returned to discover Komodo had analyzed the position 13 moves deep and was showing the position as equal.  It's recommendation began with 1...Bxg2 2.Nde4.  1...Bxg2?? is a horrible move because after 2.f3 Black loses a piece.  Houdini evaluates the position after 2.f3 as White having an advantage of over 2P's; other engines agree. 

Just to make sure Komodo wasn't seeing something in the position other engines were missing, I did some further analysis using Houdini, Komodo and Critter and managed to come up with a line where Black did get 3 P's for the pieces, but it hardly mattered because all the engines, including Komodo, agreed that Black was quite lost. 

9 comments:

  1. Oddly enough the komodo authors like to say that their engine is being geared towards playing the most human like chess.

    It does seem strong but your posts have made me think twice about using it.

    I have changed my previous thoughts on the Houdini engine (based on some comments from the author) and I have now made Houdini 2 my main engine for post game analysis and opening analysis. I also still really like Critter and Hiarcs and Junior.

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  2. Post the fen please.

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  3. here komodo shows Qc7 in short time, so your big warning is nothing to me

    btw: could you change the layout? there is one big mess on this site. all the photos are put very amateurish.

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  4. a lot of ads and suspicious stuff here. Do you really earn much money from them?

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  5. What you mean by 13 moves ahead? 26 depth or 13 depth?? If the answer is 13, its obvious you are not doing it right, since on my slow computer Komodo reach depth 22 in less than a minute.
    Another possibility is that after 5 hours, Komodo found a somewhat forced win for white after Qc7 and sees Bxg2 as its best attempt.

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  6. To answer the questions here:

    Here is the FEN
    2kr2r1/1q1b1p2/ppqRp3/2p1P1p1/8/2N1Q3/PPPN1PP1/3R2K1 w - - 0 1

    “here komodo shows Qc7 in short time, so your big warning is nothing to me btw: could you change the layout? there is one big mess on this site. all the photos are put very amateurish”

    Indeed, Komodo does show …Qc7 after a short time. After 5-1/2 hours it was showing …Bxf2. A lot of people don’t know what “ply” means so I that’s why I said 13 moves, not 26 ply. The suggestion that it may have found a win after …Qc7 so selected …Bxg2 as better is a valid point. Thanks to whomever pointed that out. I am still very skeptical of this engine’s evaluations though. Houdini, Critter, Spike, Firebird and Stockfish all seem more reliable to me.

    No. I am not going to change the layout…this IS an amateur site for my personal amusement and nothing more. Anyone who does not like it is free to move on and my feelings will not be hurt.

    Not sure what is meant by “suspicious stuff.” All ads are from legit sources, mostly Amazon, Barnes and Noble, Google Adsense and the like. As I pointed out in a previous post, even though this Blog had over 4800 hits last month I do not make any money on it because, as I said in that post, nobody buys books and equipment from chess Blogs. So why the ads? Mostly because they are books I think are likely worthwhile or interesting or because some people, like me, like to browse. Besides that, I just enjoy tinkering with the Blog.

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  7. thx for answer. of course it is YOUR blog and it can look as you wish.

    did you ran infinite analysis with one move? if so you could check the evaluation of Qc7 and reason why it was changed and when of course. Maybe it would explain sth.

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  8. It's obvious this wasn't on powerful hardware or was the 32-bit version.

    Komodo3 64 here chewing on the same position reaches depth 23 in under 2 minutes.
    And recommends Qc7 at those depths.

    Not to offend anybody but there has been performance problems with the 32-bit version of Komoodo as stated elsewhere before.

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  9. Komodo3-64 used with Fritz 12 running on an AMD Athlon II dual core laptop with 4 GB memory if that means anything to you…I do not know that much about computers.

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