20 outs on the flop against a two-thirds-pot bet: call or fold

The numbers favor a call. 20 outs on the flop reach 67.53%, and a two-thirds-pot bet asks only for 28.57%.

Verdict

Call

20 outs, flop, two-thirds-pot bet

  • Chance to hit by the rivertwo cards to come67.53%
  • Equity the call needs$66.67 into a pot of $233.3328.57%
  • Margin over the priceyour chance minus the price+38.96 points

What the numbers say

Pay the two-thirds-pot bet and you get a better deal than the draw needs. You need 28.57%, you have 67.53%, and the 38.96-point difference is large.

Think of 20 outs as a running total of every card that improves you. 20 of the 47 unseen cards qualify, which is 42.55% on one card.

Worked through on a $100 pot

  • Pot when the bet arrives$100
  • Your opponent bets$66.67
  • Your call$66.67
  • Pot with your call in$233.33
  • What a hit wins$166.67
  • You lose on a miss$66.67
  • How often you hit67.53%
  • Expected value of a call+$90.90
  • Equity needed to break even28.57%
  • Margin, to four decimals+38.9586 points
  • Fractional outs at the price7.20 outs
  • Margin measured in outs+12.80 outs

Stay with simple rules: the whole pot on a hit, the call lost on a miss, no more money in. Under them calling gains $90.90 on average. The hit side averages $112.55, the miss side $21.65, and each dollar called returns +1.364.

In odds, you face 0.48 : 1 against you and the pot pays 2.5 : 1.

The price is 28.57% because your call goes into the pot too. Leave it out and you get 40.00%, a margin of +27.5301 points that does not exist; use the starting pot instead and 66.67% puts the margin at +0.8634 points.

Reverse implied odds and your margin

8 outs is the line for a two-thirds-pot bet on the flop. Your 20 sit 12 outs above it, and the chance at the line is 31.45%.

After a hit you could give back up to $134.61 on later streets, 2.02 times your call, before the call stops paying.

Price of a two-thirds-pot call if you give money back after a hit, 20 outs on the flop
Given back laterPrice with itYour chance minus priceValue of the callCall?
$028.57%+38.96 points+$90.90Call
$1029.85%+37.68 points+$84.15Call
$2532.00%+35.53 points+$74.02Call
$5036.36%+31.17 points+$57.14Call
$10050.00%+17.53 points+$23.37Call

Which chance to use

You can skip the usual debate over one card versus two, because 42.55% and 67.53% both give a call against 28.57%.

20 outs against a two-thirds-pot bet, one view per row
Cards countedChanceMargin over priceValue of the callVerdict
By the river, two cards67.53%+38.9586 points+$90.90Call
Next card only42.55%+13.9818 points+$32.62Call

Nearby draws

Draws near yours, on the same street and against the same bet: the price is fixed at 28.57%, and each out moves the chance about 2.50 points.

Outs 16 to 20 on the flop against a two-thirds-pot bet
OutsBy the riverMarginVerdict
16 outs56.98%+28.41 pointsCall
17 outs59.76%+31.19 pointsCall
18 outs62.44%+33.87 pointsCall
19 outs65.03%+36.46 pointsCall
20 outs, this page67.53%+38.96 pointsCall

Every bet size, one draw

Bet size sets the price, so the verdict changes as you scan the table. The two-thirds-pot bet of this page is marked in the first column.

20 outs are strong enough to call every size listed. A chance of 67.53% beats even the biggest price in the table.

20 outs on the flop against every bet size
Bet sizeEquity neededMarginVerdict
quarter-pot16.67%+50.86 pointsCall
third-pot20.00%+47.53 pointsCall
two-fifths-pot22.22%+45.31 pointsCall
half-pot25.00%+42.53 pointsCall
two-thirds-pot, this page28.57%+38.96 pointsCall
three-quarter-pot30.00%+37.53 pointsCall
pot-size33.33%+34.20 pointsCall
1.25x-pot35.71%+31.82 pointsCall
1.5x-pot37.50%+30.03 pointsCall
2x-pot40.00%+27.53 pointsCall
3x-pot42.86%+24.67 pointsCall
4x-pot44.44%+23.09 pointsCall

How this is computed

The chance to hit is the exact closed form, with no simulation. From the flop, 351 of the 1,081 possible pairs of unseen cards hold no out, so the chance is 1 minus 351 / 1,081, which is 67.53%.

What is held fixed: the call equals the bet, so the price is $66.67 / $233.33 = 28.57%; the pot is won whole on a hit; there is no further betting; and each of the 47 unseen cards is as likely as any other. Opponent cards are not removed.

Computed from the closed form by the GeorgeLiPoker math library.

Updated

Questions

What is the right play with 20 outs when a two-thirds-pot bet comes on the flop?

Your chance, 67.53%, set against the 28.57% price gives +38.96 points and a call. With a $100 pot, a $66.67 call and no more betting, the average value of the call is +$90.90.

What is the fewest outs that can call a two-thirds-pot bet on the flop?

You need at least 8 outs against a two-thirds-pot bet on the flop. That count hits 31.45% against 28.57% needed, and 7 falls short at 27.84%. With 20 you are 12 past the minimum.

One card or two: which number belongs next to the 28.57% price?

Both figures are right for their own situation: 67.53% with no more betting, 42.55% when the turn brings a bet. Facing 28.57%, 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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