In my last article we saw how to break down fianchetto castled position by opening up the h-file with the help of h4-h5 lever, but sometimes your opponent can physically block the h file with the piece (usually a knight on h5/h4). In such situations it is often a good idea to sacrifice an exchange in order to open lines against the opponent’s monarch. Before sacrificing like this there is one very crucial point one must consider; there are more chances that exchange sac won’t work if your opponent can protect h7 (h2) reasonably.
Here is an example that covers the theme.
Kasparov against Piket in 1989
Q: In this position Black played 31…Bd5. How would you evaluate this move?
A: This bishop move is a mistake as it allows exchange sacrifice on h5, otherwise it wasn’t possible even with a free move for White. For example 31…a6 (just a random move) 32. Rxh5 gxh5
33. Qh4 and now Bd7 threatening to take on f5 then to protect the h7.
Let’s get back to game.
31…Bd5? 32. Rxh5! gxh5 33. Qh4
Now the …Bc6-d7 idea won’t work because of Qh3 followed by Re1>h2 threat.
34. Qxh5 Qf1+
Other moves like Rd8 or Rc8 won’t work because of Qh6! followed by Rh3.
35. Kb2 e5 36. Qh6!!
Threatening f6! & the knight is untouchable because of pin along the e file. The position is lost for Black.
If 36…f6 then 37. gxf6 Qg2 38. Ne2 wins.
and Black resigned after 3 more moves.