While working on my latest Every Move Explained, 2007 Barcelona - Krasenkow vs. Nakamura, I encountered the position shown in the diagram. Nakamura played 11...c5, an excellent move.
The tactical justification for the move was 12.dxc5 d4 13.Na4 bxc5. Now if 14.e5, then 14...Nxe5 15.Bxa8 Qxa8.
[FEN "r2q1rk1/3nbppp/bpp1pn2/p2p4/2PPP3/1PN3P1/P1QN1PBP/R1B2RK1 b - - 0 11"]
As I explained in my own notes to the game,
The Black Queen and light-squared Bishop would then operate unopposed on the a8-h1 diagonal, putting the White King at considerable risk, while the White Rooks would lack an open file to break into the Black position.
The same sacrificial theme played an important role over the next few moves, although it was never played in the game. It reminded me of the old saying that most sacrifices are in the notes to the games. Good players don't let their opponents sacrifice too easily.
To play through the complete game see...
Mikhail Krasenkow vs Hikaru Nakamura, Casino de Barcelona 2007