Komodo 9.2

lkaufman · Post by **lkaufman** » Fri Aug 21, 2015 1:43 am

We have just released Komodo 9.2 at komodochess.com. As usual it is free to subscribers and available at a 20% discount to those who bought Komodo 8 or a later version. It's been about two months since our 9.1 release so we are well ahead of our quarterly target.
The estimated rating gain at fast levels is about 15 elo, about the same as the gain from 9.02 to 9.1, so the gain from 9.02 is about 30 elo and from Komodo 8 about 80 elo. This comes from re-tuning many parameters, from improved time management, from improved move ordering and from free speedups. However the most significant change introduced in Komodo 9.2 is "Contempt", which replaces "Drawscore". This is not just a name and sign change. Contempt now incorporates the concept of trying to keep more pieces on the board until you are winning, when playing a weaker opponent. The default value of 15 (centipawns) is probably optimum for playing engines rated around a hundred elo or so below Komodo 9.2. Against a close rival (of which there is currently only one other than Komodo 9.1) best results will be obtained with a smaller contempt value, perhaps 5. Against most other engines a larger value like 20 or 25 should work even better than the default. Against humans I suggest using 40 for Grandmasters, 50 for Masters, and 75 for strong amateurs. Even larger values are suitable for handicap games. Note that in game play Contempt will cause the score reported by Komodo to be optimistic; in analysis mode (infinite search) Contempt is automatically set to zero.
The release came too late to be used in the first stage of TCEC, but of course it will be available for the second stage. We anticipate using Komodo 9.2 in Sunday's two pawn handicap match with Grandmaster Petr.

TShackel · Post by **TShackel** » Fri Aug 21, 2015 2:28 am

Hi Larry,

Thanks very much for this announcement. I'm very happy for this new form of contempt that I recommended all the top engines do (in the spirit of houdini and avoiding too many exchanges which typically lead into a drawn endgame). And I'm also happy you found increased elo with use of this contempt. It's possible that when you avoid exchanges that will make it easier to gain advantage later on in the game, whereas if you exchanged everything down early the chances of a good advantage would be nil.

Keep up the great work.

Sincerely,

Tim.

mbabigian · Post by **mbabigian** » Fri Aug 21, 2015 3:57 am

Note that in game play Contempt will cause the score reported by Komodo to be optimistic; in analysis mode (infinite search) Contempt is automatically set to zero.

Is there any way to force contempt to apply during analysis mode?

Thanks,
Mike.

lkaufman · Post by **lkaufman** » Fri Aug 21, 2015 4:06 am

mbabigian wrote:
Note that in game play Contempt will cause the score reported by Komodo to be optimistic; in analysis mode (infinite search) Contempt is automatically set to zero.
Is there any way to force contempt to apply during analysis mode?

Thanks,
Mike.

Not directly, but I suppose you could accomplish this by "playing" a game against it with a ridiculously long time control, tricking it into thinking it is not in infinite analysis mode.

mbabigian · Post by **mbabigian** » Fri Aug 21, 2015 4:17 am

Ok. Can you add a checkbox to force it on during infinite analysis as an upcoming feature? Perhaps in 9.3?

On the same subject, allowing the change of contempt during analysis without risking a hash clear would be awesome too if it doesn't preserve it already.

Congrats to your team. Another nice set of improvements!
Mike

Graham Banks · Post by **Graham Banks** » Fri Aug 21, 2015 4:24 am

lkaufman wrote:We have just released Komodo 9.2 at komodochess.com........

Looking forward to testing it.

JJJ · Post by **JJJ** » Fri Aug 21, 2015 5:13 am

15 elo at fast time control.
Is this more at mid time or long time control ?

Werner · Post by **Werner** » Fri Aug 21, 2015 5:52 am

Graham Banks wrote:
lkaufman wrote:We have just released Komodo 9.2 at komodochess.com........
Looking forward to testing it.

Me too

Werner

melajara · Post by **melajara** » Fri Aug 21, 2015 8:11 am

Larry and Mark, are you aware that another Komodo, Komodo Activestate, has been updated to 9.2 too? Are you in touch with them for some coordination? LOL

Such a funny coincidence!

See http://komodoide.com/download/

shrapnel · Post by **shrapnel** » Fri Aug 21, 2015 11:47 am

lkaufman wrote:Against a close rival (of which there is currently only one other than Komodo 9.1) best results will be obtained with a smaller contempt value, perhaps 5.

Hmm....there is a small, but perhaps significant difference between the figure stated here and that in the Official Readme of Komodo 9.2.
Which is more accurate ?
Kindly clarify.

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