What is a Combination?

I"ve seen it several times, what exACTLY is a combination??? 

A sequence of moves, often initiated by a sacrifice, which leaves the opponent few options and results in tangible gain.

http://en.wikipedia.org/wiki/Combination_%28chess%29

If the move sequence doesn't contain some sort of sacrifice, it's usually called a "forced manoever" instead of a "combination". A minor distinction.

Another way to look at it is that a combination takes a few of the basic elements... pin, fork, etc... and combines them into a single line of play.

Example:

A Pin:

A Fork:

A Pin + Fork Combination:

Thanks Mr. Ed and Emu...further down it said  "It is a series of staggering blows before the knockout."  I like that definition and it said ". . . it must be at least three moves long."    So it's just like as in boxing.  

This is from a game I just played. It was won with a sacrifice combination that set up checkmate. I was playing as white against a higher ranked opponent (black). I've annotated important moves for you.

Those are tactics, a combination is a series of forcing or threatening/near forcing moves that lead to a decisive advantage or tactic.

"By a combination we mean 'a sequence of forcing moves with a specific goal, and grounded in tactics. A sacrifice is likely to be present and Botvinnik, among others, says is always present.' -- The Oxford Companion to Chess.

After giving the above definition used by the Oxford Companion to Chess, Yusupov states that:

"The aim of a combination need not simply be mate, but can also be winning material, stalemate or promoting  pawn. . . What is most important of all is that your opponent is enticed to a forced exchange of material and has to follow through to the end of the sequence."

It's also worth underscoring -- from what I've learned -- if you are playing as white against black who opens with a Sicilian defense, it is common that black will attempt to launch a queen-side pawn attack. If, as white, you avoid trading bishops early and manage to put your knights on the King side, you're most likely going to be playing for an all-out King-side attack that will require a combination (and sacrifice) at some point.

The first two are tactics, the third is a combination based on those two tactics.

Here's an old game of mine which is virtually one long combination... and only moderately unsound.

Yes, sorry, fair enough.  I thought the first two were also being presented as "combinations".

That was beautiful combination Emu!   

Thanks. I think Black could have de-railed the combination by playing ... e6 on move 15, but I feel that I would still have had decent compensation for my Pawn sacrifice.

The nice thing about the game is that I offered first a Pawn (move 10) then a Knight (move 13), then a Bishop (move 15), then a Rook (move 16), then my Queen (move 18)... all of the pieces, in order of value.

Ha!  That is unreal.  Game of the decade! 

A miscalculation.

In fact, the game is so short and relatively forced that it wouldn't surprise me if the entire game had been played before, including my mistake on move 14... although I haven't been able to find it in a games database.

Wondering what percentage of King-side combination mates result from black opening with Sicilian...

Here's a slightly different black defense against a white King-side combination threat...