Slow Mover

[exekutive]

The 'Slow Mover' parameter is not documented by Stockfish (https://official-stockfish.github.io/docs/stockfish-wiki/UCI-&-Commands.html). It's not documented in this repo either.

No such option is listed by the engine itself:

uci
id name Stockfish 17.1
id author the Stockfish developers (see AUTHORS file)

option name Debug Log File type string default <empty>
option name NumaPolicy type string default auto
option name Threads type spin default 1 min 1 max 1024
option name Hash type spin default 16 min 1 max 33554432
option name Clear Hash type button
option name Ponder type check default false
option name MultiPV type spin default 1 min 1 max 256
option name Skill Level type spin default 20 min 0 max 20
option name Move Overhead type spin default 10 min 0 max 5000
option name nodestime type spin default 0 min 0 max 10000
option name UCI_Chess960 type check default false
option name UCI_LimitStrength type check default false
option name UCI_Elo type spin default 1320 min 1320 max 3190
option name UCI_ShowWDL type check default false
option name SyzygyPath type string default <empty>
option name SyzygyProbeDepth type spin default 1 min 1 max 100
option name Syzygy50MoveRule type check default true
option name SyzygyProbeLimit type spin default 7 min 0 max 7
option name EvalFile type string default nn-1c0000000000.nnue
option name EvalFileSmall type string default nn-37f18f62d772.nnue
uciok

so what does it do, if anything, and where is it documented?
If it is discontinued, then it should be removed.

[johndoknjas]

'Slow Mover' was removed in official-stockfish/Stockfish#4917. So for Stockfish 16 onwards, it's not a thing. This means we have a few options:

• Raise an error if the user tries to set slow mover while using a Stockfish <= v15.
• Remove 'Slow Mover' from the wrapper entirely.
• Leave the things as they are.

[gameroman]

We could show a warning for now and then remove it later