On December 3rd, future International Master Yaacov Norowitz is going to give us a lecture on playing on colored square complexes. Simply put, in a given position the combination of pawn structure and pieces on the board may give one side powerful control over connected squares of the same color. That side can then try to convert their control of these squares into a positional bind, a mating attack or even a carefully constructed defense in an otherwise hopeless situation. This can be seen very easily in positions where a fianchettoed bishop (say on g7) is eliminated, leaving the adjacent squares f6 and h6 without pawn or piece cover and open to invasion by enemy pieces. Sound simple? Perhaps, but this is a legitimately difficult concept to execute, and mastery of it is the mark of a high class player.
With any luck, Yaacov can shed some light for us. In the meantime, we'll take a look at Karpov-Shirov (Biel, 1992) which is annotated very nicely by Kasparov amongst others. In this game Karpov creates a well calculated light-square domination theme almost out of the ether.
We'll pick up the game on move 17 of a Meran Semi-Slav, where Black seems close to playing ...c5, unleashing his light-squared bishop and ensuring at least equality.
17. Ng5! (heading for e4, preventing ...c5) Qe7
18. Nce4 Nxe4
19. Nxe4 Bb4
20. Ng3! (The threat now is Nf5 and then f4, when g7 falls) f6
Black had the choice of defending the g7 square either this way or with 20...g6. I won't borrow from the detailed analysis on how White can best proceed against 20....g6, but it suffices to point out that ...g6 uncomfortably weakens the dark squares around the Black king and opens the a1-h8 diagonal further for White's bishop. This being the case, it seems very natural to play ...f6 as it seems to offer less of a target, and the dark squares are protected. But Karpov sees farther...
21. Bxe5! Qxe5 White has removed the sole protector of the light squares on Black's kingside since Black's bishop is still trapped on b7 (notice whether that bishop plays any role in this game)
22. Bd3 h6 (...g6 would have been hard to decide on because of the many possibilities for White after 23. Bxg6 hxg6 24. Qxg6+)
Now we can see that the light squares around the Black king are vulnerable, but this one weakness is not yet enough to press for a win, so Karpov positions his pieces on dominant squares then expands the field of battle.
23. Bg6 Rf8
24. Nf5 c5
25. axb5 axb5
26. Ra7 Qc6
27. Nh4 Rxd1+
28. Qxd1 Ra8 (threatening to take another pair of major pieces off the board when it seems like Black might hold)
29. Qg4!! Qc6 (29...Rxa7?? 30. Qe6+ Mate in two)
30. Rxb7! Qxb7
31. Qe6+ Kh8
32. Be4 Resigns
When 32....Ra1+ 33. Kh2 Qb8+ 34. f4 is not going to stop White from mating using the Q-B-N combination on the light squares. Notice the absence of Black's pieces from the Kingside and the iron grip that White has on f5, g6, and even f7. White's pieces can move interchangeably on the light squares and create new problems at will for Black. About this game Kasparov noted 'Shirov...in this game did not make a single bad move (but a whole series of second-rate ones)'. For all of us who make nothing but second-rate moves, this makes for a powerful demonstration.
The ability to conceptualize the transition from the top position (seemingly equal) to the bottom one (utterly winning) is what Yaacov will now teach us, in one easy lesson!