This is problem 671 in The Ultimate Chess Puzzle Book: 1001 Original Chess Puzzles to Challenge All Standards of Player, from Beginner to Grandmaster, by John Emms.
We’ll look at this position in some detail.
It’s white to play. We can immediately observe white’s superior piece activity by contrasting white and black’s rooks and bishops, although black has a small amount of compensation due to a superior pawn formation. Based on his superior piece activation, white either has to come up with an attack or risk going into a long drawn-out slug fest. Black only needs a little time to organize his pieces, so we need to ask if white can gain an immediate edge.
Since this is a tactical problem, we know there is a tactic! It’s pretty clear that the tactics revolve around a king-side attack. White’s bishop is putting pressure on h7, white’s queen is pressuring g7, and the h6 pawn is ready to advance to h6 to put more pressure on g7. White’s rook could eventually come to f7 to put pressure on g7, or perhaps there is an opportunity for a rook lift.
The challenge is not foreseeing the the tactic, but being certain that the combination actually works. There are indeed a number of tricky moves for black.
1. Bxh7+ is most forcing. If black does not accept the sacrifice with 1. …, Kh8, then clearly 2. Rf7 looks to require black to at least give up his queen for a rook.
1. Bxh7+, Kxh7 and now the g6 square is available to the queen, which will then support Rf7. Black is up a piece, and so there is no stopping now.
2. Qg6+ and black needs to decide between Kg8 and Kh7. Black needs to be able to play Qg8 to defend g7. For example, 2. …, Kg8 3. Rf7, and now black is forced to play 3. …, Qf8 to prevent mate.
Fritz indicates that 4. Rxd7 is best. However, white’s king is exposed. If this were a tournament game, I might be inclined to play 4. Rxf8 and get black’s queen off the board.
So we now have the sequence 1. Bxh7+, Kxh7 2. Qg6+, Kh8 3. Rf7, Qg8, and the only natural move is 4. h6 with a threat of mate in two.
If this were a tournament game in which I was black, I would not even consider 4. …, Qxf7, since this surrenders significant material. I don’t care if the computer says this is the better move. Better to stoically play on and hope for a break.
So 4. …, Qh7 5. hxg7+, Kg8 6. Rf8+, Rxf8 7. Qxh7+, Kxh7 8. gxf8+(Q) and white wins. Note that each of white’s moves in this sequence are completely logical and do not require analysis. (However, foreseeing these moves from the beginning is entirely another matter.)
Are we done? No. Let’s continue to utilize this puzzle to study some other ideas…
Suppose that it was black’s turn in this position rather than white’s. Knowing that white has the above combination, what should black play? 1. …, h6 is out of the question, since white can play 2. Qg6 and has force mate. A fairly obvious candidate that covers both f7 and g6, guards the critical pawn at e6, and clears the back rank is 1. …, Qe7.
Fritz seems to have a slight preference for Be8. Crazy computers! This seems to free up the queen. Not that it would be good, but black could then play Bf7 and the bishop transforms into a glorified pawn. For me, I seek dynamic piece activity, and would play Qe7.
Now let’s look at this another way. Suppose you’re playing white and it’s your turn, but suppose that you do not see the above tactic or are too uncertain to play it. What would you do instead?
One option is 1. h6, putting immediately pressure on g6. Does this work? 1. …, g6 is not an option due to 2. Bxg6 and white has an excellent attack. So black has to protect g7 with 1. …, Qe7. Now what does white do? This is not a position that warrants passivity, so the natural move is 2. hxg7, with the threat of 3. Bxh7+ (although Fritz strongly prefers a rook lift with 3. Rf4).
So now 2. …, Qxg7 and I don’t think white should exchange queens in this position, although it is a tough win for black with the slightly superior pawn structure.
QED