McBrain 2017

[Tdunbug]

What is the purpose of "study" mode?

[MikeB]

What is the purpose of "study" mode?

A more comprehensive look at positions at the cost of lower depth and ELO. Part of Stockfish's great playing strength is due to the very sophisticated way it culls the search tree - through null move and other pruning functions in search.cpp. Although this clearly best from an ELO perspective , in a few , relatively rare positions , it will all cull the best move. Joe Ellis develop the study code in matefinder. The only thing I added to Joe's code was that I also turned multi-pv on as that will help. If Stockfish does not find the correct solution say to a test position , that many weaker engines find , it will often find the solution in study mode. Another use is for people who are using Stockfish for correspondence chess, one would always want to check the position in study mode , particularly if Stockfish returns a move and score for a position that is not given by Stockfish in normal mode. That's all really. Stockfish (McBrain) will play several hundred ELO weaker with study mode on , but it will see somethings that normal Stockfish may never see in certain positions.