I honestly don't think you can calculate percentages without knowing what the size of the pot relative to the money already in is. By the time you know you *might* be up against aces, you're probably already deep into the betting. So, heads up, KK vs. AA might go:
($1/2, 100 BB effective)
KK: Raise to $8
AA?: Raise to $25
KK: Raise to $75.
AA?: Shoves for $200.
You're now getting 125/400 pot odds - 31.25%. And Kings cracking Aces is 18.05%.
Hand | Pot equity | Wins | Ties |
---|
KK | 18.05% | 10,986,372 | 285,228 |
AA | 81.95% | 50,371,344 | 285,228 |
Now let's say you call and you're wrong. In that case, your EQUITY is $72 (400 * 18%). Since your last bet -- the only one where you can REALLY suspect that opponent has aces -- is only $125, you're looking at an EV of $72 - 125 = -$53 to call.
So reverse it: if you fold and are right, you effectively gain +$53.
But let's take a look at the other scenario. Let's give opponent a range of QQ+, AK (still very tight!) -- AND we're including Aces in the range there -- that's important, because sometimes you are right that the read is that "he'd do it with queens or AK, too", but this time he has it...
Hand | Pot equity | Wins | Ties |
---|
KK | 57.19% | 117,843,360 | 11,091,132 |
QQ+, AK | 42.81% | 86,815,812 | 11,091,132 |
So calling here is $228 on a $125 bet. So that's $228 - 125 = $103
And reverse it - if you fold and are wrong, you're effectively *losing* $103.
Calling and being wrong costs about half as much as folding and being wrong.
If you
really want to put a number on it (and I don't recommend it) -- if you really want the answer to the question: "How often do I have to fold and be right here," the answer is 103/(103+53) =
66% of the time. That's a LOT of times for a poker player to be right, especially when inexperienced.
Of course, that changes when the stacks get a lot deeper. Now let's say that we're sitting on ($1000) or 500bb each. Now the action goes:
KK: Raise to $8
AA?: Raise to $25
KK: Raise to $75.
AA?: Raises to $250 -- this is where you have to suspect whether your opponent has aces.
Now you have a decision to make. You can shove, but in that case, you're betting $925 to win a pot of $2000.
This time, if you shove and run into aces, your EQUITY is $360. Since your last bet was $925, your EV is $360 - 925 = $-565
Reverse it - fold and you're right, and you effectively gain $565.
On the other hand... let's say you fold and are wrong. Your EQUITY is $1140, and your EV is $1140 - 925 = +$215
In this case, calling and being wrong costs twice as much as folding and being wrong! -- see how the stack sizes make a difference?
In this case - very deep stacked, 215/(565+215) = 27.5%. When you ARE deep stacked -- and I mean really deep stacked, it *can very well* be the right move to fold kings.
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In the case of the deep stacks, I think kings should just *call* the 5-bet most of the time, rather than folding. Think about it...
Let's put opponent on QQ+, AK again. Before the flop, KK has 57% equity. Decent.
But after the flop, we're going to have a TON more information about where we stand in the hand.
Let's say the board flops A 2 7 -- that's not good for us. We still have equity against QQ, but QQ is likely to fold to a bet and/or check behind. (because you could have AK or AA!), so we can't get any more money, really. If opponent bets (and it'll be a shove), we have to put them on AA/AK, against which we're a MASSIVE dog of 1.82 Easy fold.
Hand | Pot equity | Wins | Ties |
---|
KK | 1.82% | 19,944 | 1,620 |
AA | 98.18% | 1,118,916 | 1,620 |
But if the board flops three cards J or lower... we still have 62% equity, and opponent will likely shove his entire range...
Of course, he'll always do it with aces, too.
Hand | Pot equity | Wins | Ties |
---|
KK | 9.36% | 212,616 | 1,620 |
AA | 90.64% | 2,066,724 | 1,620 |
Now we're being asked to call $750 into a pot of $2000. If it's just aces, our equity is $180 (it went down quite a bit), but if it's the entire range, our equity is $1248.
The cost of calling incorrectly against *just* aces is $180 - 750 = $-570. The cost of folding incorrectly against a wide range of hands is -( $1250 - 750 = $390) = -$500. -- now the numbers work out to be a lot more even, and given that there are WAY more combos of QQ + AK + KK than there are AA...
Of course, this is ignoring all the flops that are king-high and you're just HOPING that opponent has AA...
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One final note: I talked about tournaments before. It is true that you're shorter stacked in tournaments than in cash games, so if we were looking at just the pure pot odds, I'd say it's *never* right to be folding KK preflop if you can GII. *However* your *last* chip is more valuable than your top chip... and there's of course the fact that losing everything is WAY WORSE than doubling up is GOOD. Sometimes you DO fold KK --- but in most of the cases where you would fold KK, you might *also* fold AA!