Fun With Double-Exchange Sacs
When I was a teenage Sicilian Dragon aficionado, I salivated over the thought that one day I might land in a certain theoretical sub-variation of the Yugoslav Attack where Black sacrifices not one but both exchanges to bust up White’s queenside-castled king position.
Sacking rook for minor piece twice in the same game clearly generates more than two times the thrill of a lone exchange sacrifice.
Removing defenders and perforating the enemy king’s pawn cover are two of the most widely used weapons in any attack. When you are pursuing your opponent’s king and his knight or bishop defends one or more critical squares in the vicinity, an exchange sac comes under consideration.
In the following game, White gave up rook for knight on two successive moves on the same square (d7), enabling him to decisively penetrate the dark squares around Black’s seemingly well-guarded king. It’s interesting that neither sac directly fractured the Black pawn structure – i.e., no doubled pawns were created. Instead, the damage stemmed purely from the abrupt disappearance of both black pieces that defended the vital f6 square.
In the second illustration, the defender’s pawn cover was already breached long before the fireworks began. Black had unwisely advanced his g- and h-pawns of his own volition on moves eight and nine, which effectively prevented him from castling kingside. But White still faced a challenge of breaking through, since black bishops and knights on e7, d7 and d8 (assisted by the black queen and potentially, by the rook) kept guard over the likeliest penetration points, the f7 and e6 pawns and the hole on f6.
White solved the problem by again giving up both his rooks for black minor pieces on d7. The first sac, on move 19, eliminated a crucial defender of f6, allowing the white queen to occupy that square after the forced trade of bishop for knight. From f6 the queen could threaten mate on e7 or f8 (after a possible Bc5), while also eyeing the advanced black h-pawn, were it to be left undefended by a move such as …Rf5.
Five moves later, a second exchange sacrifice on d7 softened up the e6 pawn’s defense, making possible the decisive 25.Nxe6+ (Bxe6 would have been much weaker, since after 25…Qe7 the queens come off leaving Black with a material advantage and his king no longer endangered).
Our third example differs in major ways from the first two. The exchange sacrifices occurred 21 moves apart, and both were tied to strategic goals (attaining advanced passed pawns) rather than mating opportunities.
Objectively, Neither sac represented White’s best choice. Black had to find several non-obvious moves to overcome the onslaught of pawns and minor pieces; but my opponent, a strong grandmaster, proved equal to the task. (The game with notes by IM Mark Ginsburg and a contribution from me can also be found on Ginsburg’s blog.)
If there is a useful generalization to be drawn from the preceding games, it might run something like this:
Sacking both exchanges can become feasible when all of the following conditions are satisified:
- Assaulting a king’s hideout (typically castled, whether short or long).
- The absence of any open or half-open files on that side of the board.
- An attack spearheaded by pieces and not pawns (a pawn storm usually aims at opening a file, and open files are meant for rooks).
- The enemy’s minor pieces provide critical protection to one or more squares near his king – whether those squares are occupied by pawns or not.
- Your queen is positioned to quickly occupy the critical square or squares near the enemy king once their protection is eliminated.