Players castling on opposite sides presents imbalances that usually result in attacks at both kings simultaneously. Each move or tempo is crucially important in which side succeeds first. However, one of the Secrets of Chess is that as Black you must first equalize your position before you attack, otherwise your attack will “run out of steam” fast.
In the game below our Dr. Nimzo (aka Chis Stychinsky) decides that his attack is better than Black’s in the Daily Match with the Badgers Brook Chess Club of Broxburn Scotland. Watch how the Doctor writes a prescription for an attack on Black’s king:
The move 12. Ng5 starts an all-in approach toward the attack of Black’s king, while 12…Qa5?! commits Black to an attack on White’s king, but at the cost of separating the Queen from the defense of his own kingside.
In retrospect 12.… Bxa2 is an improvement. With White’s 15. g4 he plans to shove the pawn down black’s throat with g5-g6. 16.…Nd7? is an error; better is 16. cxd3. White’s 20. Bh6? is dubious at best, but it does have the aspect of being a strong psychological move (Secret #2!) that must have been a shock to Black. This type of move is much more suited to shorter time limit games. Black is now focused on the defense of his monarch and wants to remove pieces with the regrettable 22.…de4??. However the calm 21.…Qc7!-Qf4 solves Black’s problems. White proceeds with a surgically precise combination with 22. Rhg1! and the stunning Rxd7 from which there is no way out for Black. Way to go Chris!