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Evaluating Sharpness using LC0's WDL

In the section titled Calculation of the Score, the formulas are not showing up for me. I'm not sure if it's a browser issue of mine or if something went wrong on your end.

In the section titled Calculation of the Score, the formulas are not showing up for me. I'm not sure if it's a browser issue of mine or if something went wrong on your end.

Thanks for pointing this out, it's fixed now.

Thanks for pointing this out, it's fixed now.

Some interesting implication for cheat detection perhaps? If a player can find accurate moves with high "sharpness", that seems like a stronger indicator of cheating than if they same happens with low sharpness.

Some interesting implication for cheat detection perhaps? If a player can find accurate moves with high "sharpness", that seems like a stronger indicator of cheating than if they same happens with low sharpness.

I don't know much about cheat detection but it's certainly more complicated than just looking at one number. I would leave the cheat detection to the chess websites since they have all the necessary data.

I don't know much about cheat detection but it's certainly more complicated than just looking at one number. I would leave the cheat detection to the chess websites since they have all the necessary data.

well clearly, but it might be useful to consider.

well clearly, but it might be useful to consider.

@jk_182 said in #3:

Thanks for pointing this out, it's fixed now.

The formula shows up now, but I think there is a typo. In your previous article*, you add the log terms, but in the formula for this article you are multiplying them. I think adding them makes more sense because in that case sharpness is infinite only when W/D/L = 0.5/0/0.5. If you multiply the terms, then you get infinite sharpness any time either W=0.5 or L=0.5. That would include the can't-lose situation 0.5/0.5/0 and the can't-win situation 0/0.5/0.5, which doesn't really make sense to me.

@jk_182 said in #3: > Thanks for pointing this out, it's fixed now. The formula shows up now, but I think there is a typo. In your previous article*, you add the log terms, but in the formula for this article you are multiplying them. I think adding them makes more sense because in that case sharpness is infinite only when W/D/L = 0.5/0/0.5. If you multiply the terms, then you get infinite sharpness any time either W=0.5 or L=0.5. That would include the can't-lose situation 0.5/0.5/0 and the can't-win situation 0/0.5/0.5, which doesn't really make sense to me. * https://www.chess-journal.com/evaluatingSharpness2.html

Yes, it was a typo, thank you.

Yes, it was a typo, thank you.

what would be interesting is a bot that always chooses the sharpest move (whilst trying to minimize the centerpawn loss) - I guess it would make a lot of sacks and create interesting games

what would be interesting is a bot that always chooses the sharpest move (whilst trying to minimize the centerpawn loss) - I guess it would make a lot of sacks and create interesting games

You should take a look at the LC0 WDL contempt feature (https://lczero.org/blog/2023/07/the-lc0-v0.30.0-wdl-rescale/contempt-implementation/). With this, you can basically tell Leela that she's playing against a lower rated opponent and here play will be sharper.
There are a couple of bots on Lichess with this feature for odds play:
https://lichess.org/@/LeelaQueenForKnight
https://lichess.org/@/LeelaKnightOdds
Also take a look at GM Matthew Sadler's videos about this feature: https://www.youtube.com/watch?v=u9i71vdm_Ew&list=PLxhvNMc95Uo9N6W48TUAyIwkjK0w1wHKj&index=10

You should take a look at the LC0 WDL contempt feature (https://lczero.org/blog/2023/07/the-lc0-v0.30.0-wdl-rescale/contempt-implementation/). With this, you can basically tell Leela that she's playing against a lower rated opponent and here play will be sharper. There are a couple of bots on Lichess with this feature for odds play: https://lichess.org/@/LeelaQueenForKnight https://lichess.org/@/LeelaKnightOdds Also take a look at GM Matthew Sadler's videos about this feature: https://www.youtube.com/watch?v=u9i71vdm_Ew&list=PLxhvNMc95Uo9N6W48TUAyIwkjK0w1wHKj&index=10