The Move You Can't Afford to Miss

Imagination is a vital component of every attacking player's arsenal. When attacking, it is easy to assume that a certain move or sequence is forced, thereby allowing your opponent to build up a sudden defensive bastion or attain counterplay.

In particular, zwischenzugs (in-between moves, also known as intermezzos) are very easy to miss, precisely because they occur in-between an ostensibly forced sequence of moves.

Let's look at how zwischenzugs can be found, why they are so strong, and why you can't afford to miss them. 

To begin, here's a quick example to illustrate the potency of a well-timed zwischenzug -- even when it looks fairly innocuous. 

Notice that 12.f6 did not immediately win the game. Rather, it weakened Black's kingside to such an extent that he was unable to develop his pieces in time to halt the onslaught.

In nine cases out of 10, a zwischenzug answers a capture (or threat) with a check or counter-threat. 

In Janowski-Steinitz, 12.f6 met a capture (10...Nxb3) with a threat (Rxe7+), distracting Black's attention and forcing a very serious concession.

Quite often, zwischenzugs are even more deadly. In the following game, Garry Kasparov comes up with three (yes, three!) stunning zwischenzugs in a row to round off the attack. 

young Kasparov via wikipedia

The queen sacrifice was especially difficult to see; the vast majority of players would have went 25...Qc2 without a second thought, allowing White to obtain saving chances in the endgame. 

Intermezzos can be very useful defensive tools as well. In the following titanic battle, Black is able to outplay his much stronger opponent with a beautiful and hard-to-see intermezzo. Unfortunately, he did not follow up in convincing fashion and White escaped with a draw, but the zwischenzug was certainly not to blame! 

24...e5 is a very hard move to see because it is outwardly counterproductive; to open the fifth rank, Black temporarily clogs it up even further. To bravely strike in the center while your king is under a vicious attack requires sharp tactical vision and nerves of steel.

It is a pity that Black did not follow through on multiple occasions. 

Endgame zwischenzugs can also be extremely powerful. In the next game, Vishy Anand utilizes an intermezzo "only" to gain a tempo, but it is more than enough to shatter White's defenses.

As you can see, zwischenzugs are played for very different purposes, but their essence (meeting one threat with another) remains the same. The lesson should be clear: many recaptures and retreats are indeed forced, but you should always be on the lookout for zwischenzugs -- even in the most unexpected moment, an intermediate move can win the game or save the day.

I will leave you with an exercise from one of my own games. Thinking that the game was over, my opponent resigned, missing a stunning double zwischenzug: