I am currently rewriting a chess engine with a friend. We decided to first work on the search and only later if the search works really well, we will do some very good evaluation.
The engine itself evaluates the board with pure material evaluation + piece square tables. We hit around 6Mnps and it competes with 2000 CCRL engines right now.
I was wondering how much ELO-Gain could we expect if we replace the evaluation at some point with another evaluation. Or more like: How much ELO can an evaluation function give?
I mean obviously, if you would replace the evaluation of stockfish with nothing but 0, it would do random moves and lose over 3000 ELO points but I am talking about the ELO difference between a very basic evaluation function and an insanely good evaluation function which takes mobility, king safety, pawn structure, game phase, etc. into account.