The smothered mate figures highly in any book dealing with tactical themes. It is yet another example of a mating pattern that chess authors like to make readers aware of either in order to demonstrate the powers of the pieces or to warn players that such a mate can occur. Most readers will absorb the information without really expecting it to appear in practical play. But it does appear in over-the-board play!
My largest database contains over five million games ranging from the days of Greco up to the present time. In all those games there are 91 that end in a smothered mate and quite probably many more that are resigned before the player becomes "smothered." Of course, this mate is not solely reserved for White, Black can play the same sequence of moves. The database contains roughly half the games being won by Black. In the following exposition of the theory, this should be born in mind.
The most common smothered mate pattern is shown in the following diagram.
White has just delivered mate by Nf7.
Of course, smothered mate can occur on other parts of the board and in other patterns, but the above is the most commonly seen.
As stated above, my database contains some 91 games ending in this mate, some of which were played by juniors, but the list does contain a game played by two illustrious players - Timman v Short. This game is shown below and it must be said that Nigel Short displayed fine sportsmanship by allowing his opponent to construct the mate, when he could have resigned the game much earlier and denied that chance.
The start of the mating combination is a queen check along the a2/g8 diagonal and this check can cover any distance i.e. it could be delivered successfully from a2 as long as Black cannot block the check with a supported pawn or piece. However, the further away from e6 that White uses to deliver the check, the less likely it is to succeed as there is more likelihood that the check can be resolved by the interjection of a pawn or piece. Another criteria for the combination to succeed is the ability of a knight to reach the f7-square after the queen check. It really does not matter what square the knight leaves to make this check. Of course, the knight must be able to survive the check. Sometimes it can be captured by a rook standing on f8 and this means that the only damage suffered by Black is the loss of the exchange.
All very simple criteria, but difficult to obtain.
Unlike the Greek Sacrifice manoeuvre, there is no main opening that leads to smothered mate. The Greek Sacrifice in many cases arises from a French Defence in which White has played e5 thus either driving away a black piece from f6 or preventing a defensive piece using that square.
Now some games to illustrate a few points.
It is not necessary that the mate takes place behind two pawns sheltering the doomed king as the game Adler - Wallhoever shows.
The game Rabovszky - Gyomber shows that White does not have the prerogative on smothered mates.
An example of the mate being applied to Black on the queenside can be seen in the game Azzouz - Deloffre.
Black carries out the mate against a White king whose pawns have been weakened in the game Costello - Schuh
These should be enough to demonstrate how the smothered mate is executed and the fact that it is something other than a pretty sequence of moves to decorate a discourse on mates. It is truly something that must be born in mind during most of the games we play.
The database that I have compiled for the purpose of this article from an up-dated MegaBase 2011 can be downloaded HERE in zipped PGN format.