29 Apr 09
Originally posted by WumpusThat was my guess, too. Your reasoning makes sense, but I just had to try to verify the hypothesis for Rybka.
You're actually completely correct... mobility of pieces are something highly evaluated in many chess engines. Until I added it to mine, Vicki was very happy with blocked in bishops and an utterly cramped position.
In this case, the bishops, queens and the rooks have "free" reign and to Rybka that is definitely worth a point or two.
I set up a position at move 1 with only the two kings and the eight white pawns, in their original positions. Rybka's eval started at +8.25 at ply 2. (It quickly increased as soon as it got to enough plies to realize it could queen a pawn.) So I think that proves it. 🙂