Grand Prix Variation
I've come to this position in my recent attempt to familiarize myself with the black side of the Sicilian Defense. Here's a typical position in the Sicilian where black and white attack on opposite sides of the board. White had just played 24. f5, obviously seeking complications via f6 and also hanging the g pawn in exchange for an open g file.
As theory dictates, black must play aggressively in the queenside especially in this case where white castled long. So, I battered white's position with 24... b5. Just what the doctor ordered! Play went on 25. g4 b4. I considered 25... bc 26. dc immediately opening the b file but it also means that the bishop on e4 can aid in the defense of the queenside. Play continued with 26. ab cb and now the threat of 27... b3 trapping the knight is very real.
I forgot who said it first, but one principle in chess is that when you continually apply pressure on your opponent he will make a mistake somewhere along the line. No pressure, no mistake. Keep creating problems for your opponent to solve, and he will ultimately crack. Such is the case with 27. na1? This is just an outright blunder, a lapse in judgment that was probably triggered by the threat of b3. White's defense collapsed like a house of cards after 27... qa1+ 28. kd2 qb2+ 29. kd1 ba4#.
Going back a few moves to the beginning of black's attack in the queenside, Fritz4 suggested that after 24... b5, white could have played 25. bd5 re1 26. qe1 qe1 27. ne1 bg3 with a fighting chance left to him in the kingside.