[knuckleheads]

I'm not a chess engine guy, but I've talked to some, and, from what I recall, there is a very interesting difference between an engine like Leela Chess Zero (lc0) and Stockfish. Stockfish internally calculates in centipawns while lc0 calculates in WDL's. Stockfish has a model they use that converts their centipawn calculation to WDL's, but it's not _really_ WDL of the position, it's just their estimate of it according to a probabilistic model. Same in reverse applies to lc0. Why I find this interesting is that it shows how they come from different generations, with Stockfish representing the old deterministic style with deep search, and lc0 being directly inspired by Alpha Zero and the new generation of engines based on neural nets. Stockfish has by now adopted the best of both worlds (deep search with a small neural net) and is the better for it, but I still think the developers of both engines banter over who is really producing the True WDL numbers for a given position.

For my part, I find that WDL is more amendable to interpretation. Being up 5 pawns worth of material sort of makes sense, but being told you have a 95% chance of winning makes more sense to me at first blush.

[n_e]

> but I still think the developers of both engines banter over who is really producing the True WDL numbers for a given position

In fact, stockfish's WDL is very rudimentary: it is a function of the centipawn evaluation of the position and the value of the remaining material.

See https://github.com/official-stockfish/Stockfish/blob/a6d055d...

[knuckleheads]

Yeah, it's still unclear to me why Stockfish produces WDL numbers beyond sometimes people ask for them.

[tarentel]

To your last point, the centipawns thing doesn't make a whole lot of sense from an interpretation perspective because it is so shallow. WDL can give you much more insight into how tame or chaotic things are. A 1 pawn evaluated advantage with a 95% chance to win is wildly different from a similar evaluation and a 50% chance to win. The first position likely has an obvious tactic that leads to a win, the latter may require perfect play for 15 moves that only a computer can calculate.

Also, from a computer perspective, a >= 1 pawn is usually sufficient for a computer to win 100% of the time so it's not really interesting and says very little about whether a person could win 100% of the time.

[knuckleheads]

Yep, exactly. I spent a lot of time trying to figure out better ways for interpreting the evaluations of engines for https://www.schachzeit.com/en/openings/barnes-opening-with-d... and I ended up liking WDL much better than centipawns. A blunder defined in terms of decreasing your chance of winning by such and such percentage is, to me, a much better definition than a blunder losing such and such material. What does that mean? It makes sense to me now, but it took a long while.

Relatedly, there is an interesting thing that lc0 has been doing as well, where it takes the contempt concept even further, and can beat you with queens odd. https://lczero.org/blog/2024/12/the-leela-piece-odds-challen... It assumes it is better than you and that it shouldn't just give up because you might be up a knight, rook or even queen.

[ramblerman]

If there is a 15 move sequence that leads to a guaranteed win, stockfish would not call it a 1 pawn advantage (given the sufficient calculation time) instead calling it a won position.

I think you may be mistaking your understanding of stockfish as shallow in that regard.

Where the big differences might emerge is in strategic mid game positions without any clear tactics or forcing moves. There lc0 can somehow "feel" that a position seems better.

[deklesen]

FWIW, as an avid chess player, I find the "up 5 pawns" has more intuitive signal.

[knuckleheads]

Was it intuitive when you were first learning to play? Or have you gotten used to understanding positions via centipawns?

[recursivecaveat]

It's always made as much sense to me as being up or down money in Monopoly, or points in basketball. Stating the W/L value of a position feels like an weird mixing of the present and future to me. Of course the centipawn value holds an implicit prediction of the future, but the indirection makes it more palatable.

[deklesen]

I learned chess when I was 5, and didnt have a chess computer in the first like 5 years and by then I have progressed quite far.. so i cannot really tell

[knuckleheads]

Makes sense. I started learning how to play Chess when I was ~30 and my tutors were just chess engines, game reviews on chess.com and whatever books I found interesting enough to get through. I have fun, and that's all I'll ever have, no titles or anything. The centipawn stuff makes sense now, but it took a while.