Forking the enemy queen and knight in order to force a queen exchange, thus pre-empting a potential white attack.

The exchange of bishops will make the e5-pawn more vulnerable.

Preferable was 5.Nc4 Rd5 6.Rd1 Ra7 7.Rxd5! exd5 8.Ne3! with chances for a draw.

Thanks to his sounder pawn structure Black is better in the endgame.

Preparing 2 Be5 to swap the attacker on c7.

1...Qxc6?! 2.Rc1 Qd7 3.Qd4 , followed by 4 Rfd1, the d5-pawn turns into a problem for Black.

Parrying the threats of 6 b5 and 6 Qxd5.

Thanks to the eternal weakness on c6, White keeps a slight advantage.