The following is the first lesson from General Treatise on Chess by Roberto Grau (from now on referred to as GTC).
Material Vs. Time
Piece value is based on what the pieces are doing and not because the piece is on the board.
The following example shows how an advantage in time can be superior to a material advantage.
Schories vs. Spielmann Schevenningen 1905
Black to move after move 12.
White is threatening to win a pawn after 13.Bxe4. Spielmann reasons that White’s lack of queenside development (the knight and bishop are still on the back rank) and a possible opening of the –file are worth more than a pawn, so he played 12…f5!. 13.exf6 e.p Qxf6 14.Bxe4 dxe4 15.Qxe4 Bb3! a magnificent maneuver. Spielmann takes away the c2 retreat from the Queen, and plans to gain time with Rac8. Notice how Black has all of his minor pieces in the game, and he will economically bring the rook into play. White on the other hand, has a knight on f3 which cannot move because of the threats against f2. 16. c4? A mistake. If you are behind in development you should avoid advancing pawns, because this leads to an additional loss of time. 16.Be3 was undoubtedly better. 16…Qd6 17.Nbd2 When you are behind in development you are at a much greater risk of being attacked. Because of this it is always prudent to simplify the position. Simplification favors the defender. For this reason 17.Qd5+ returning the material and leading to an inferior endgame is White’s best chance. 17…Rae8 18.Qb1. White has to continue relinquishing squares in order to maintain his material advantage. The situation is now becoming critical.
18… Nd4! Spielmann has managed to combine his space advantage with the weakness on f2. White cannot play 19.Nxd4 Qxd4 20.Nxb3 because of the pretty combination 20…Qxf2+ 21.Rxf2 Re1++. If 20.Nf3 Qxc4 with a clear advantage for White.
19. Ne4 Nxf3 20. fxg3 Qg6+ 21.Kh1 Rxf3A simple and definite maneuver that not only recovers the pawn for Black but also leads to a victory. If 22.Nxc5 Bc2 23.Qa2 Rxf2!, with an inevitable mate coming, and if 24.Rg1 Re1, etc.
22. Re1 Rxf2 23. Bg5 Qh5 24. Nf6+ gxf6 25.Rxe8 Kf7 0-1.