Upgrading to Lc0 v0.21.1 in CuteChess

This a quick note for people who use CuteChess and just upgraded to v0.21.1 from earlier versions.

Meaning of FPU-related parameters are changed in v0.21.1 , along with default values of those parameters.

If you upgraded your Lc0 to v0.21.1 in CuteChess by just replacing the files, most probably CuteChess still remembers old defaults and sets them.

To make CuteChess see correct default values, either install Lc0 v0.21.1 as a fresh engine, or try pressing “Detect” / “Restore to defaults” in engine settings in cutechess.

After update, there should be:

  • no FpuReduction parameter,
  • FpuValue should be equal to 1.20000 (was -1.00000 before the change)

UPD : Similar issue also happens in Arena. The fix is similar: “Restore to defaults” in engine settings, or reinstall the engine fresh.

Posted by: crem