Nordlandia wrote:Set contempt=0 for analysis, case solved
No! Don't turn it off!
What Eelco de Groot says is true: what matters is what moves are chosen by the engine, not their scores, and Stockfish outputs better moves with higher Contempt, I have used this since the new Contempt was implemented (note, this Contempt isn't new, it has been out for a while, what is new is that it's the default), and the higher Contempt stands in correspondence time controls.
Is 20 too high? No, actually, you can actually go higher as long as you interact and compare the analysis with other engines. Actually.
This is also true for Komodo and Houdini.
Houdini has a very interesting implementation of Contempt, it seems to detect what side is winning and try to apply Contempt to this side, so you can see really huge swings of evaluations as Houdini goes from liking one side, to liking the other in the next ply.
With Contempt you don't want to analyze both sides of the board, though. If you have analyzed from the white side, what you need to do to have a consistent analysis from the black side is to reverse contempt (say, switch to -20 when you switch sides.) But then you might miss comebacks from this side.
So what you really want to do is have two different Stockfishes loaded in different GUIs, one only analyzes the white side and provides optimistic scores for this, the other only analyzes the black side and does as such for black.
This has been like this for Komodo for a while, and you actually have to create different personalities for Komodo's white side and for Komodo's black side in your GUI.
I'm not sure a checkbox that would apply the 0.20 Centipawns as score shifts so the engine would show consistent scores for white and black would work. First, because, really, white and black should be using differen trees:
White assumes black will play defensively and try to draw, black assumes white will play defensively and try to draw, this produces better moves for both sides. Second, even with a Contempt of 40, Stockfish is showing scores of 0.00 for drawn positions, if all the ideas are refuted by the opponent, this would translate to a score of -0.40 for those equal positions, or a change to a worse move if there's some really -0.39 move that the engine would prefer, wrongly.
Users just need to learn about this concept of using different instances of Stockfish depending on the side of the board they analyze, and to propagate different scores for white and black's viewpoints.