4 outs on the flop against a pot-size bet: call or fold

The numbers favor a fold. 4 outs on the flop reach 16.47%, and a pot-size bet asks for 33.33%.

Verdict

Fold

4 outs, flop, pot-size bet

  • Chance to hit by the rivertwo cards to come16.47%
  • Equity the call needs$100 into a pot of $30033.33%
  • Margin over the priceyour chance minus the price-16.87 points

The price of the call

16.47% against 33.33%: the draw trails the price by 16.87 points. On this flop against a pot-size bet, that is an easy fold.

If you are on a gutshot straight draw, this is your count: 4 outs among 47 unseen cards, or 8.51% on a single card.

A $100 pot, step by step

  • The pot before betting$100
  • The bet$100
  • Your call$100
  • Final pot if you call$300
  • What a hit wins$200
  • Loss on a miss$100
  • Chance to hit by the river16.47%
  • Expected value of calling-$50.60
  • Equity the call needs33.33%
  • Margin, to four decimals-16.8671 points
  • Outs that exactly reach the price8.53 outs
  • Outs above the price-4.53 outs

Stay with simple rules: the whole pot on a hit, the call lost on a miss, no more money in. Under them calling loses $50.60 on average. The hit side averages $32.93, the miss side $83.53, and each dollar called returns -0.506.

Put as odds, the draw is 5.07 : 1 against, and the pot offers 2 : 1 for the call.

Watch the pot you divide by. Leaving your call out turns 33.33% into 50.00%, and the margin into -33.5338 points.

The extra winnings a call would need

Implied odds are the way to close the gap. You need $307.30 more on later streets after hitting, which is 3.07 times the call you make.

The smallest count that pays for a pot-size bet is 9 outs at 34.97%. You hold 4, which is 5 outs fewer.

Price of a pot-size call with future winnings added, 4 outs on the flop
Future winningsPrice with themYour chance minus priceValue of the callCall?
$033.33%-16.87 points-$50.60Fold
$5028.57%-12.11 points-$42.37Fold
$10025.00%-8.53 points-$34.14Fold
$25018.18%-1.72 points-$9.44Fold
$50012.50%+3.97 points+$31.73Call

By the river or next card

The two chances agree on the verdict. 16.47% by the river and 8.51% on one card each lead to a fold against 33.33%.

4 outs against a pot-size bet, one view per row
Cards countedChanceMargin over priceValue of the callVerdict
By the river, two cards16.47%-16.8671 points-$50.60Fold
Next card only8.51%-24.8227 points-$74.47Fold

Nearby draws

Draws close to yours, on the same street and against the same bet: the price is fixed at 33.33%, and each out moves the chance about 3.89 points.

Outs 2 to 6 on the flop against a pot-size bet
OutsBy the riverMarginVerdict
2 outs8.42%-24.92 pointsFold
3 outs12.49%-20.84 pointsFold
4 outs, this page16.47%-16.87 pointsFold
5 outs20.35%-12.98 pointsFold
6 outs24.14%-9.19 pointsFold

Other bet sizes for this draw

One draw, 12 bets. Each row gives the equity the call needs, the margin over it, and the verdict for 4 outs on the flop.

Even the smallest bet on the list outprices 4 outs on the flop. The break-even bet is 0.25 times the pot ($24.55 on a $100 pot), and every one of the 12 sizes is above it.

4 outs on the flop against every bet size
Bet sizeEquity neededMarginVerdict
quarter-pot16.67%-0.20 pointsFold
third-pot20.00%-3.53 pointsFold
two-fifths-pot22.22%-5.76 pointsFold
half-pot25.00%-8.53 pointsFold
two-thirds-pot28.57%-12.11 pointsFold
three-quarter-pot30.00%-13.53 pointsFold
pot-size, this page33.33%-16.87 pointsFold
1.25x-pot35.71%-19.25 pointsFold
1.5x-pot37.50%-21.03 pointsFold
2x-pot40.00%-23.53 pointsFold
3x-pot42.86%-26.39 pointsFold
4x-pot44.44%-27.98 pointsFold

How this is computed

The chance rests on counting, not on a rule of thumb. Blank pairs: 903 out of 1,081; hit chance: 16.47%.

Keep the assumptions in view: a full call ($100 into $300, or 33.33%), the whole pot on a hit, no more betting, and 47 unseen cards that are equally likely. The math does not know what the other player holds.

Computed from the closed form by the GeorgeLiPoker math library.

Updated

Questions

What does the math say about calling a bet of the full pot with 4 outs on the flop?

Reduce the question to a comparison of two numbers: 16.47% to hit and 33.33% to break even. The first minus the second is -16.87 points, which makes this a fold, and the call averages -$50.60 on a $100 pot if no more betting follows.

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

9 outs is the line. At 9 the chance is 34.97%, enough for 33.33%; one fewer gives 31.45%, which is not. Your 4 outs sit 5 below it on the flop, at 16.47%.

Is the by-the-river chance the right one to use on the flop?

The river figure of 16.47% assumes no further betting; the next-card figure of 8.51% assumes you pay again on the turn. Against 33.33%, both say fold, so you can use either.

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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