White still has to develop his knight at b1. This piece has only a future at square c3, to contest the centre. But when the knight is put at c3, it blocks the bishop at b2. So 10.Nc3 (option B) is not a good move. The bishop at b2 and the pawn chain d2-e3-f4 are not a good combination because they both perform the same task, to contest the black squares. The white squares around the pawn chain have to be defended by other pieces. If the bishop at b2 is exchanged, it is only in whites favor. With 10.Be5! (option A) followed by 11.Nc3, white can complete his development. As a rule of thumb in Steinitz elements of chess, white should first put his pieces to the best squares before playing a pawn move. This means that 10.e4 (option C) is not the best move because it does not solve the problem with knight b1. Position 15 is the game Toscani Tremblay (4.36). – is a queen up, but he has a minor problem with his first rank. White can improve his position by enlarging the activity his pieces with, for example 40.Rdd1. In the game white played carelessly 40.Rxc1?? After 40…Rxc1+ 41.Rd1 black won the game with 41…Qe1+! The sad part of the story was that the accident did not happen in time trouble. White only violated the rule of thumb by worsening the activity of his pieces with one move… Chess can sometimes be cruel!
White still has to develop his knight at b1. This piece has only a future at square c3, to contest the centre. But when the knight is put at c3, it blocks the bishop at b2. So 10.Nc3 (option B) is not a good move. The bishop at b2 and the pawn chain d2-e3-f4 are not a good combination because they both perform the same task, to contest the black squares. The white squares around the pawn chain have to be defended by other pieces. If the bishop at b2 is exchanged, it is only in whites favor. With 10.Be5! (option A) followed by 11.Nc3, white can complete his development. As a rule of thumb in Steinitz elements of chess, white should first put his pieces to the best squares before playing a pawn move. This means that 10.e4 (option C) is not the best move because it does not solve the problem with knight b1. Position 15 is the game Toscani – Tremblay (4.36). is a queen up, but he has a minor problem with his first rank. White can improve his position by enlarging the activity his pieces with, for example 40.Rdd1. In the game white played carelessly 40.Rxc1?? After 40…Rxc1+ 41.Rd1 black won the game with 41…Qe1+! The sad part of the story was that the accident did not happen in time trouble. White only violated the rule of thumb by worsening the activity of his pieces with one move… Chess can sometimes be cruel!