I just finished a 6 handed SNG, and while no particular hand stood out, what did stand out was the play of my heads-up opponent.
Near the end, we were pretty close to even in chips and I got pocket jacks and managed to get it all in and win the pot. That gave me a nearly 4:1 chip advantage. He was left with just short of $2000 with the blinds at $50/$100. So that gave him an M of 13, for those of you who use that as a measure, or 20 big blinds, if you measure it that way.
Now, I can understand playing carefully when you're short-stacked and there are a bunch of players left, or you're on the money bubble, but we were heads-up, so both of us were going to cash. I would suggest that that's the point where just about the only decision you have left is all-in or fold. But this guy was a real stone - he would fold to raises, wait to see a flop and then fold... It took 25 hands and whittling him down to about $600 before he would commit to a hand... whereupon he committed to bottom pair when I just happened to have flopped a straight. He did go all-in a couple times before the flop (when I had garbage), but when you're down that far heads-up, I think you need to gamble a bit more. When you get down that low, doubling-up through your opponent is just as risky as it ever is (if you're short-stacked by $1 and lose, you're just as gone as if you were down to your last chip and lose) when you're short-stacked. Conversely, your opponent can call or push you with much worse hands because your short stack is not a sufficient threat. So the bigger your stack, the more pressure you can put on your opponent with an all-in. The smaller your stack, the more meaningless your move is, and the less reward you get for your risk.