Fishtest SPRT Elo

[tall tapir]

I've been trying to find the formula to calculate these values.

So I can set up an excel spreadsheet, enter in the game results and it will automatically calculate the LLR/Elo.

LLR    -0.00 [-2.94,2.94]
Elo    -0.00 [-1000.00,1000.00] (95%)
LOS    50.0%
Games    0 [w:0.0%, l:0.0%, d:0.0%]
Pentanomial    [0, 0, 0, 0, 0]```

I've already looked at fishtest-mathmatics and clicked on all the links to the pdfs. The pdfs are full of very high level university level equations/maths.  I've looked at the source code but I can't understand it.

[umbral crystal]

You'll have better luck asking it in the fishtest repo, as the one that created the math isnt in this discord

As for LLR theres 5 different formulas for it

The one that fishtest uses involves maximum likelihood estimation

Which involves a root finding algorithm

So not very easy to incorporate to an excel spreadsheet

[next grove]

Maybe this can help? https://elocalculator.netlify.app/

[tall tapir]

I've been trying to find a link to the fishtest discord, but I can't find one anywhere. Do you have a link?

[umbral crystal]

There is no fishtest discord, if you want to talk with the man in charge of fishtest mathematics michel "vdbergh" van den bergh you can reach him through fishtest github

[tall tapir]

Thanks that helps. It calulates the 'Trinomial statistics' which I also need.
I can't quite get it to match the actual live elo difference.

The elo difference 'https://tests.stockfishchess.org/tests/live_elo/66e8ab2386d5ee47d953aba8' here is different to the one on https://abrok.eu/stockfish/ 'Date: Tue Sep 17 21:01:43 2024 +0200.'

[cerulean spire]

@tall tapir Abrok is a third party, so we cannot guarantee the safety, reliability, and availability of those binaries because we are not responsible for them.
Therefore, we only recommend downloading from the official GitHub releases.

[umbral crystal]

The one on the website is regular pentanomial elo, the one on fishtest is sprt-bias adjusted elo