Stockfish Level Settings on LiChess

[BrendanJNorman]

I currently have a small competition among all of the stronger kids I coach where they are to compete who can beat Stockfish with BOTH colors at the highest level setting.

See image.



You will see that I have also included myself as a reference for them, having beat all versions of Stockfish up to level 6.

But level 7 seems very strong. I have only managed a draw thus far, but have had very promising positions (my liChess rating drifts between late 2300s- nearly 2500).

At the same time, I have students who are literally little kids who have beaten level 5.

My question is this:

Does anyone know anything about this weakened version of SF they're using and how strong the settings are?

How do they relate to the downloadable SF's levels? The same?

Thanks guys.

[Chessqueen]

I currently have a small competition among all of the stronger kids I coach where they are to compete who can beat Stockfish with BOTH colors at the highest level setting.

See image.



You will see that I have also included myself as a reference for them, having beat all versions of Stockfish up to level 6.

But level 7 seems very strong. I have only managed a draw thus far, but have had very promising positions (my liChess rating drifts between late 2300s- nearly 2500).

At the same time, I have students who are literally little kids who have beaten level 5.

My question is this:

Does anyone know anything about this weakened version of SF they're using and how strong the settings are?

How do they relate to the downloadable SF's levels? The same?

Thanks guys.

Those students of your that have beaten level 5, have they tried beating Stockfish with Rook Odds ? which should be almost equivalent.

[BrendanJNorman]

I currently have a small competition among all of the stronger kids I coach where they are to compete who can beat Stockfish with BOTH colors at the highest level setting.

See image.



You will see that I have also included myself as a reference for them, having beat all versions of Stockfish up to level 6.

But level 7 seems very strong. I have only managed a draw thus far, but have had very promising positions (my liChess rating drifts between late 2300s- nearly 2500).

At the same time, I have students who are literally little kids who have beaten level 5.

My question is this:

Does anyone know anything about this weakened version of SF they're using and how strong the settings are?

How do they relate to the downloadable SF's levels? The same?

Thanks guys.

Those students of your that have beaten level 5, have they tried beating Stockfish with Rook Odds ? which should be almost equivalent.

Nope. The idea is to play training games that are similar to REAL CHESS.

Not some exhibition match. Rook odds is just a spectacle IMHO.

Also, the idea of all of them playing the same Stockfish (LiChess's version) on the same platform, is to keep variables constant.

A good way to compare the strength and relative improvement of each kid.

Winning is hardly the point, although it makes them happy!

Here is one of my kids sending me the winning position vs level 5 today.



Lots of fun.

[Chessqueen]

I currently have a small competition among all of the stronger kids I coach where they are to compete who can beat Stockfish with BOTH colors at the highest level setting.

See image.



You will see that I have also included myself as a reference for them, having beat all versions of Stockfish up to level 6.

But level 7 seems very strong. I have only managed a draw thus far, but have had very promising positions (my liChess rating drifts between late 2300s- nearly 2500).

At the same time, I have students who are literally little kids who have beaten level 5.

My question is this:

Does anyone know anything about this weakened version of SF they're using and how strong the settings are?

How do they relate to the downloadable SF's levels? The same?

Thanks guys.

Those students of your that have beaten level 5, have they tried beating Stockfish with Rook Odds ? which should be almost equivalent.

Nope. The idea is to play training games that are similar to REAL CHESS.

Not some exhibition match. Rook odds is just a spectacle IMHO.

Also, the idea of all of them playing the same Stockfish (LiChess's version) on the same platform, is to keep variables constant.

A good way to compare the strength and relative improvement of each kid.

Winning is hardly the point, although it makes them happy!

Here is one of my kids sending me the winning position vs level 5 today.



Lots of fun.

How long have you trained this Kid that sent you the winning game at level 5 ?

[BrendanJNorman]

I currently have a small competition among all of the stronger kids I coach where they are to compete who can beat Stockfish with BOTH colors at the highest level setting.

See image.



You will see that I have also included myself as a reference for them, having beat all versions of Stockfish up to level 6.

But level 7 seems very strong. I have only managed a draw thus far, but have had very promising positions (my liChess rating drifts between late 2300s- nearly 2500).

At the same time, I have students who are literally little kids who have beaten level 5.

My question is this:

Does anyone know anything about this weakened version of SF they're using and how strong the settings are?

How do they relate to the downloadable SF's levels? The same?

Thanks guys.

Those students of your that have beaten level 5, have they tried beating Stockfish with Rook Odds ? which should be almost equivalent.

Nope. The idea is to play training games that are similar to REAL CHESS.

Not some exhibition match. Rook odds is just a spectacle IMHO.

Also, the idea of all of them playing the same Stockfish (LiChess's version) on the same platform, is to keep variables constant.

A good way to compare the strength and relative improvement of each kid.

Winning is hardly the point, although it makes them happy!

Here is one of my kids sending me the winning position vs level 5 today.



Lots of fun.

How long have you trained this Kid that sent you the winning game at level 5 ?

Just over a month.

[Fritz 0]

Stockfish levels don't work in my Fritz GUI at all. If they did, I could compare them with Komodo/Dragon levels.

[MonteCarlo]

See https://lichess.org/forum/game-analysis ... ?page=3#26 for an explanation of the levels.

Cheers!

[BrendanJNorman]

See https://lichess.org/forum/game-analysis ... ?page=3#26 for an explanation of the levels.

Cheers!

This is EXACTLY what I was looking for! Thanks!

[BrendanJNorman]

I believe that is currently correct. Lichess seems to be using the UCI option 'Skill Level' and other means to weaken Stockfish.
See these and further down in that code where the variables LVL_MOVETIMES and LVL_DEPTHS are used to set things up for the "go" command.
github.com/niklasf/fishnet/blob/53e218bd184554265748513f85d19e601f18c310/fishnet.py#L117-L119
github.com/niklasf/fishnet/blob/53e218bd184554265748513f85d19e601f18c310/fishnet.py#L818

So I think the 1-8 'level' is used to index into these:
LVL_SKILL = [0, 3, 6, 10, 14, 16, 18, 20]
LVL_MOVETIMES = [50, 100, 150, 200, 300, 400, 500, 1000]
LVL_DEPTHS = [1, 1, 2, 3, 5, 8, 13, 22]

Edit: This is an old blob. Looking for the current code.
The new code seems to work in similar fashion, though now the SF range of levels extends to negative values!
github.com/niklasf/fishnet/blob/master/src/api.rs#L221-L270
The move times remain the same as above. The skill is mapped as [-9, -5, -1, 3, 7, 11, 16, 20].
The depth is now mapped as [5, 5, 5, 5, 5, 8, 13, 22].

https://lichess.org/forum/general-chess ... ?page=4#33

Very interesting.

[Ovyron]

Excuse the language, but this seems like a half-assed implementation. At the lower levels luck is going to be the main factor of how often it blunders and how bad the blunder is, so that by pure luck level 5 could play weaker than level 4, just completely inconsistent.

Stockfish naturally comes with a curve of strength, Depth 1 is weaker than Depth 2 which is weaker than Depth 3, which is weaker than Depth 4, which is weaker than Depth 5. It is a shame that they don't take advantage of this and instead set it to 5 and throw dice to decide how it plays.

A student could lose to level 1 and beat level 5, there's no progression if you're unlucky. Blegh.