This weakens Black's King's side. R - K 1 was the right move.
12. P - K R 4
12. ........
P - K 4
This is merely giving up a Pawn in order to come out quickly with his Q B. But as he does not obtain
any compensation for his Pawn, the move is bad. He should have played Q - Q 4 and tried to fight the game out that way. It might have continued thus: 13. Q - B 4, B - Kt 2; 14. Q × B P, B × P; 15. Kt × B, Q × Kt; 16. O - O - O with considerable advantage of position for White. The text move might be considered a mild form of suicide.
13. P × P
B - B 4
14. Q - K B 4
B × B
15. O - O - O
B - Kt 2
16. R × B
Q - K 2
17. Q - B 4
In order to keep the Black Queen from coming into the game.
