[xom]

« Assuming Anand and Carlsen’s blunders were independent events, what we saw was a 1 in 10,000 occurrence. »

Are they independent events though? In a game between mediocre players, if there is only one move to take advantage of a blunder, the computer analysis will repeatedly cry "blunder!" each turn until either that move is played or the initial blunderer defuses the opportunity. As for grandmaster play, I have no clue.

[jdoliner]

My hypothesis would be that GMs are much less likely to blunder when there's a winning move on the board. They're generally very good at finding such moves.