Desperado

There are two types of situations that may provoke a Desperado:

Type 1, where both sides usually have Hanging Pieces and you decide to go banzai and try to take your opponent's piece(s) out ... before your piece snuff's it.

Type 2, when you want to force a Draw (Stalemate) by "threefold repetition*"

* Threefold Repetition - when the same position occurs three times, without progress being made, a player can claim a draw (this suits a player who would, otherwise, lose the game).

Let's take a look at examples from both definitions ...

Type 1
- Where Both Sides Have Hanging Pieces -

... Nxg3
hxg3 ... Bxe5

Historical Game:
Petrosian-Fischer, 1958

Prior to the moves being made, you can see the two Hanging Pieces - Petrosian's (White) e5 Knight and Fischer's (Black) h5 Knight ...

Hanging simply refers to the fact that a piece has no support, which makes it vunerable to attack.

In this example, White has just been (his Knight moved from f3 to capture Black's e5 Pawn), leaving Black's h5 Knight threatened from White's Queen, in that Discovered Attack.

If Black proceeds to capture White's e5 Hanging Knight, with his g7 Bishop, he will lose the Knight, in addition to that already-captured e5 Pawn, leaving him a piece down against White.

Here's how Black maintains material equality:

Move 12, Black makes the Desperado manoeuvre by using his Hanging kNight to capture (x) White's Pawn, on g3 - effectively sacrificing his Knight, in the process.

Move 13, White uses his h-file Pawn to capture (x) Black's Knight, on g3; Black then sends his Bishop to capture (x) White's Knight, on e5.

Type 2
- When You Want To Force A Draw -

h4 ... Re2+
Kh1 ... Qxg3
Qg8+ ... Kxg8
Rxg7+

Historical Game:
Evans-Reshevsky, USA, 1963

Evans (White) saw he was losing this game and, as ½ a point for a Draw (Stalemate) is better than zero for a Loss, here's what he did to achieve his new objective.

Move 47, White advances his h-file Pawn to h4; Black drops his Rook to e2, putting White's King in "Check" (+).

Move 48, White drops his King out of Check, to h1; Black chooses to close in on White's King, by sending his Queen to capture (x) Black's Pawn, on g3.

Move 49, White makes the first of two Desperado moves by sending his Queen to g8, which places Black's King in "Check" (+) ...

Black cannot resist and uses his King to deal with his own threat, by capturing (x) White's Queen, on g8.

Move 50, White makes his second sacrificial move, by using his Rook to capture (x) Black's Pawn, on g7, again placing Black's King in "Check" (+) ...

Black must deal with the threat - either with his King or Queen ...

But, by capturing White's Rook - which must be done - means White's only remaining piece, with space to move, will be the King ...

White's King won't be able to move, as it'll put him in "Check" - an illegal move.

As White's King won't be in Check on his h1 square, and with no more legal moves, the game will end in a Draw (Stalemate) ...

And it came, courtesy of this second type of Desperado move.