It depends on the state of the game. In a congested pawn chain dominated game, definitely a knight. At the end with big open lines, probably a bishop, but it all depends. Sometimes individual players have a personal preference too. Petrosian , for example, liked knights, apparently.
I wouldn’t promote to a bishop in the Lasker Trap, but a knight wins you the game
BISHOP OR KNIGHT ??!!
WHO IS THE BEST ?
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