After tactical considerations piece activity plays one of the key roles in deciding upon the quality of a move, and this is especially the case in the endgame. In Capablanca – Tartakower, New York 1924 White was even ready to sacrifice material in order to have the more active pieces:
Question: What do you think about this position? Make a plan for White.
White’s rook looks really great on the 7th rank but on the other hand White can’t defend his pawns on the queenside. After Bxf5 White will get passed pawn on g file and Capablanca judged that getting his king to f6 is more important than material.
1…Rxc3+ 2. Kg4 gxf5 3. Kxf5 is winning for White.
In this position White can restore the material balance with Ke2 followed by Rd7, but it is far from winning. On the other hand if he can get his king into f6 he will force Black’s rook to go passive position and then White can eat Black’s pawns easily.
3.Kh4 Rf3 4.g6! Rxf4+ 5.Kg5 Re4 6.Kf6!!
The only winning move. After 6. Kxf5 game is draw because Black rook is no longer forced to occupy the passive position. For instance 6…Rxd4 7. Kf6 Rf4+ 8. Ke5 Rc4 9. Kxd5 is a draw.
6…Kg8 7.Rg7+ Kh8 8.Rxc7 Re8
It is worth comparing the two rooks.
9.Kxf5 Re4 10.Kf6 Rf4+ 11.Ke5 Rg4 12.g7+ Kg8
Black can not capture on g7 as the resulting king and pawn endgame is simple win for White.
13. Rxa7 Rg1 14. Kxd5 Rc1 15. Kd6 Rc2 16. d5 Rc1 17. Rc7 Ra1 18. Kc6 Rxa4 19. d6