Newbie question: Are actual checkmates fairly rare at top level chess tournaments? By this I mean that the checkmate was either played, or could have been forced. Or is it true that most GM games end in a draw? What are the statistics?

There are really few exceptions when the game is played to the checkmate. The games are usually decided long before checkmate, either by inevitable loss of material (yes, they sometimes resign even 1-2 moves before actually losing material) or when there is a simple checkmate, that the GMs are sure not to miss.

I don't know the exact number of draws, but amongst the 2700+ players it might be up to 50%, amongst GMs with bigger rating difference (100-200 ELO points) the number of draws decreases significantly.

We are talking about the elite of the chess players on the world, who would have no problem to beat all non-titled players on hte world simultaneously :) Amongst players of our level it is good to play as long as possible (why not trying even a piece down?).

Here are some interesting statistics based on 1005 games from major tournaments.

There were 658 wins, and...

95 percent ended by resignation

Another 3 percent ended in checkmate

Time forfeiture accounted for 1.2 percent

One tenth of one percent ended because they began because of absence forfeit-one of the players failed to show up

There were 357 draws, and...

83 percent ended by agreement of the two players

Perpetual check accounted for 10.7 percent

The similar claim, repitition of position, occured 4.6 percent of the time

Stalemate ended 1.2 percent of the games

And 0.5 percent were drawn when one player claimed correctly that his opponent had insufficient mating material

Just thought this stuff was interesting

If there is a checkmate between good players, the person who on the defending side almost always sees it before the final move is played. Letting it to be played anyway is really just a sort of courtesy or, something of aesthetic value, or on the other hand not wanting to leave go. Only in some really extraordinary circumstances such as time trouble could a top level player miss or hope his opponent was going to miss a checkmate in one.

It's kind of similar with draws. Of all the draws that were agreed, a huge fraction of them would have come from a forced draw situation.