Do you call 13 outs on the flop when he has an overpair?

Hm, I've come up with slightly different calculations than both of fatguy and newfish; here's how I see it:

Assume we hold T, 9 versus villain's K,K

Flop is
9, 8, 7

We have 13 outs:
Two 9s
Four 6s
Four Js
Three Ts
= 13

Here's the stove:

Code:

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 990  games     0.001 secs   990,000  games/sec

Board: 9d 8h 7s
Dead:  

                equity         win           tie        pots won    pots tied    
Hand 0:     54.141%      52.93%     01.21%      524       12.00   { KhKs }
Hand 1:     45.859%      44.65%     01.21%      442       12.00   { Td9h }


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So we have 45.859% equity versus the overpair. Basically, we can call for our stack depending solely on whether the amount of dead money in the pot overtakes the importance of our disadvantage in equity.


Example 1: Hero and Villain's stacks are 100$ each; 15$ already in pot

Villain is all-in for 100$; we must pay 100$ to win 115$; this implies we need 46.5% equity, which we do not have; so we fold.


Example 2: Stacks are same as in (1) except there is now 40$ already in the pot

Villain is all-in for 100$; we must pay 100$ to win 140$; we now require 41.67% equity, which we have; thus we call.