15 outs on the flop against a third-pot bet: call or fold

The numbers favor a call. 15 outs on the flop reach 54.12%, and a third-pot bet asks only for 20.00%.

Verdict

Call

15 outs, flop, third-pot bet

  • Chance to hit by the rivertwo cards to come54.12%
  • Equity the call needs$33.33 into a pot of $166.6720.00%
  • Margin over the priceyour chance minus the price+34.12 points

Chance against price

With 15 outs on the flop you hit 54.12% of the time by the river, and a third-pot bet only asks for 20.00%. That 34.12-point cushion makes this a clear call.

Holding a flush draw with an open-ended straight draw gives you exactly 15 outs, out of 47 unseen cards. One card hits 31.91% of the time.

Worked through on a $100 pot

  • The pot before betting$100
  • Bet$33.33
  • Your call$33.33
  • Total pot after calling$166.67
  • Net gain when you hit$133.33
  • Loss on a miss$33.33
  • Chance to hit by the river54.12%
  • Average value of the call+$56.86
  • Price of the call20.00%
  • Exact margin over the price+34.1166 points
  • Outs at break-even4.91 outs
  • Margin measured in outs+10.09 outs

Assume the whole pot goes to you when you hit, the call is lost when you miss, and nothing more is bet. Calling then gains $56.86 on average: $72.16 from hits, minus $15.29 from misses, +1.706 per dollar called.

Odds say the same thing. Hitting is 0.85 : 1 against, and the pot lays 4 : 1.

Do not forget your own call. Dividing the bet by the pot without it gives 25.00%, not 20.00%, and would show a margin of +29.1166 points. The bet over the starting pot, 33.33%, is worse and would show +20.7832 points.

Slack in the call

If some outs turned out to be shared with a better hand, you could give up 10 outs and still call. The floor is 5, at 20.35%.

After a hit you could give back up to $105.07 on later streets, 3.15 times your call, before the call stops paying.

Price of a third-pot call if you give money back after a hit, 15 outs on the flop
Given back laterPrice with itYour chance minus priceValue of the callCall?
$020.00%+34.12 points+$56.86Call
$1021.28%+32.84 points+$51.45Call
$2523.53%+30.59 points+$43.33Call
$5028.57%+25.55 points+$29.80Call
$10050.00%+4.12 points+$2.74Call

Next card or river

You can skip the usual debate over one card versus two, because 31.91% and 54.12% both give a call against 20.00%.

15 outs against a third-pot bet, one view per row
Cards countedChanceMargin over priceValue of the callVerdict
By the river, two cards54.12%+34.1166 points+$56.86Call
Next card only31.91%+11.9149 points+$19.86Call

How the answer moves with outs

One out can change the answer, so the table lists the counts on either side of 15. Each out adds roughly 2.87 points against the 20.00% price.

Outs 13 to 17 on the flop against a third-pot bet
OutsBy the riverMarginVerdict
13 outs48.10%+28.10 pointsCall
14 outs51.16%+31.16 pointsCall
15 outs, this page54.12%+34.12 pointsCall
16 outs56.98%+36.98 pointsCall
17 outs59.76%+39.76 pointsCall

Other bet sizes for this draw

Look down the margin column to see where the draw stops paying. Every row uses 15 outs on the flop and a bet of a different size.

A draw this strong has no ceiling inside the table. 54.12% tops every price from the smallest bet to the largest.

15 outs on the flop against every bet size
Bet sizeEquity neededMarginVerdict
quarter-pot16.67%+37.45 pointsCall
third-pot, this page20.00%+34.12 pointsCall
two-fifths-pot22.22%+31.89 pointsCall
half-pot25.00%+29.12 pointsCall
two-thirds-pot28.57%+25.55 pointsCall
three-quarter-pot30.00%+24.12 pointsCall
pot-size33.33%+20.78 pointsCall
1.25x-pot35.71%+18.40 pointsCall
1.5x-pot37.50%+16.62 pointsCall
2x-pot40.00%+14.12 pointsCall
3x-pot42.86%+11.26 pointsCall
4x-pot44.44%+9.67 pointsCall

How this is computed

The hit chance comes straight from combinations. Out of 1,081 pairs of unseen cards, 496 miss every out, so you hit 54.12% of the time.

Four assumptions sit behind the verdict: you call the full bet, a hit wins the entire pot, no money goes in after the call, and every one of the 47 unseen cards is equally likely. The price is $33.33 / $166.67 = 20.00%. No card is taken out for what an opponent might hold.

Computed from the closed form by the GeorgeLiPoker math library.

Updated

Questions

Does the math favor calling a third-pot bet with 15 outs on the flop?

Reduce the question to a comparison of two numbers: 54.12% to hit and 20.00% to break even. The first minus the second is +34.12 points, which makes this a call, and the call averages +$56.86 on a $100 pot if no more betting follows.

How strong must a draw be to call a third-pot bet on the flop?

A call starts to work at 5 outs: 20.35% to hit versus 20.00% needed. One out fewer drops the chance to 16.47%. You hold 15, which is 10 more than the minimum.

One card or two: which number belongs next to the 20.00% price?

Both figures are right for their own situation: 54.12% with no more betting, 31.91% when the turn brings a bet. Facing 20.00%, each one gives a call.

Check your own hands against the numbers

Bring a hand you played and we will work through the price, the chance to hit and the decision together.

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