13 outs on the flop against a half-pot bet: call or fold

Facing a half-pot bet on the flop with 13 outs, the call is correct: 48.10% to hit against 25.00% needed.

Verdict

Call

13 outs, flop, half-pot bet

  • Chance to hit by the rivertwo cards to come48.10%
  • Equity the call needs$50 into a pot of $20025.00%
  • Margin over the priceyour chance minus the price+23.10 points

Reading the verdict

With 13 outs on the flop you hit 48.10% of the time by the river, and a half-pot bet only asks for 25.00%. That 23.10-point cushion makes this a clear call.

Think of 13 outs as a running total of every card that improves you. 13 of the 47 unseen cards qualify, which is 27.66% on one card.

Putting dollars on the call

  • Pot when the bet arrives$100
  • The bet$50
  • Your call$50
  • Pot after your call$200
  • You can win on a hit$150
  • You lose on a miss$50
  • Probability of a hit48.10%
  • Expected value of a call+$46.21
  • Break-even equity25.00%
  • Margin, to four decimals+23.1036 points
  • Outs that exactly reach the price6.23 outs
  • Outs above the price+6.77 outs

Suppose a hit wins the entire pot, a miss loses your call, and no more betting follows. The average gain is $72.16, the average loss is $25.95, and calling gains $46.21 on average, or +0.924 per dollar called.

Odds say the same thing. Hitting is 1.08 : 1 against, and the pot lays 3 : 1.

One easy error is to use 33.33%, the bet over the pot before your call, as the price. The right price is 25.00%, and the mistaken margin would be +14.7703 points. The bet over the starting pot, 50.00%, would claim -1.8964 points.

Reverse implied odds and your margin

The fewest outs that still call a half-pot bet on the flop is 7. You hold 13, so you have 6 outs to spare before the call flips to a fold.

If hitting means paying off a bigger hand later, the call survives a loss of $96.06. That is 1.92 times the $50 call.

Price of a half-pot call if you give money back after a hit, 13 outs on the flop
Given back laterPrice with itYour chance minus priceValue of the callCall?
$025.00%+23.10 points+$46.21Call
$1026.32%+21.79 points+$41.40Call
$2528.57%+19.53 points+$34.18Call
$5033.33%+14.77 points+$22.16Call
$10050.00%-1.90 points-$1.90Fold

One card or two

No conflict here: 48.10% for two cards and 27.66% for one both give a call against the 25.00% price, so you need not decide which view applies.

13 outs against a half-pot bet, one view per row
Cards countedChanceMargin over priceValue of the callVerdict
By the river, two cards48.10%+23.1036 points+$46.21Call
Next card only27.66%+2.6596 points+$5.32Call

Counts close to yours

Draws close to yours, on the same street and against the same bet: the price is fixed at 25.00%, and each out moves the chance about 3.05 points.

Outs 11 to 15 on the flop against a half-pot bet
OutsBy the riverMarginVerdict
11 outs41.72%+16.72 pointsCall
12 outs44.96%+19.96 pointsCall
13 outs, this page48.10%+23.10 pointsCall
14 outs51.16%+26.16 pointsCall
15 outs54.12%+29.12 pointsCall

Changing the bet, keeping the draw

Look down the margin column to see where the draw stops paying. Every row uses 13 outs on the flop and a bet of a different size.

The call holds at every one of the 12 sizes. 48.10% is higher than the price of even the largest bet.

13 outs on the flop against every bet size
Bet sizeEquity neededMarginVerdict
quarter-pot16.67%+31.44 pointsCall
third-pot20.00%+28.10 pointsCall
two-fifths-pot22.22%+25.88 pointsCall
half-pot, this page25.00%+23.10 pointsCall
two-thirds-pot28.57%+19.53 pointsCall
three-quarter-pot30.00%+18.10 pointsCall
pot-size33.33%+14.77 pointsCall
1.25x-pot35.71%+12.39 pointsCall
1.5x-pot37.50%+10.60 pointsCall
2x-pot40.00%+8.10 pointsCall
3x-pot42.86%+5.25 pointsCall
4x-pot44.44%+3.66 pointsCall

How this is computed

The hit chance comes straight from combinations. Out of 1,081 pairs of unseen cards, 561 miss every out, so you hit 48.10% of the time.

The numbers are a baseline rather than a prediction for one hand. The price is 25.00%, from $50 into $200, and the chance assumes a whole pot won on a hit, no more betting, 47 equally likely unseen cards, and no cards removed for the other player.

Computed from the closed form by the GeorgeLiPoker math library.

Updated

Questions

Does the math favor calling a half-pot bet with 13 outs on the flop?

The verdict is call. Your chance is 48.10% and the price is 25.00%, which leaves +23.10 points. On a $100 pot with a $50 bet, calling is worth +$46.21 on average if the whole pot is won on a hit and nothing more is bet.

What is the minimum number of outs for a half-pot bet on the flop?

Against 25.00%, the first count that works on the flop is 7, at 27.84%. At 6 the chance is 24.14%, too low. Compared with that threshold, your 13 outs are 6 above.

Which chance should you compare with the price, the next card or the river?

Match the number to the betting: 48.10% if all-in or checked down, 27.66% if you face another bet on the turn. The price is 25.00%, and both numbers agree on 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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