[Maroon]

Well, it's not a given that your opponent has AA, even if he's the most obvious-playing fish in the world. Such players will usually go all-in with AK also.

Once we assume you have KK, there are six ways that this person can have AA, and eight that he can have AK. So of the fourteen holdings that the most obvious-playing fish in the world would have, you're beating 57% of them. (I am not saying your chances of winning are 57%, I'm just saying, preflop, you're ahead of 57% of his possible holdings).

As Sklansky says, you want to avoid close calls early in the tournament, so perhaps you might not call here, if you could be sure he would go all-in with only AA or AK.

But let's say the guy is a slightly better player, and thus he would go all-in with QQ. There are sixteen ways he could hold that. Now, you're ahead of 24 of his 30 possible holdings, or 80%. (Again, I am not saying you will win 80% of the time, just that you're ahead of 80% of the hands he would go all-in with). So you'd be crazy not to call.

I might go all-in with AQ suited, but I would definitely not do so with AQ off. So, we won't get into that, but you can do the math yourself.

By the way, it's better to go all-in before the flop with KK than to call, because if an Ace flops it's easy to be outplayed. You just have to hope you don't get trapped by Aces, because when AA and KK bump heads in no-limit, usually someone is losing his whole stack.