// spot check · flop

Open-ended straight draw vs top pair, pot-size all-in on the flop

Villain shoves 10 bb into a 10 bb pot on the flop.

Your hand
9♣8♣
Board
T♠7♦2♥
Facing
10 bb into 10 bb
Villain range: custom · 56 of 80 combos live
AT,KT,QT,JT,T9s,77,22

Villain has top pair (any ten with a broadway kicker, or T9s) or a set. No draws, no bluffs.

Fold−0.49 bb for calling
31.7% equity against 33.3% needed

What it shows

An open-ender has eight clean outs, which is less than the nine of a flush draw, and the sets take some of them away. It lands just short of the third it needs. Make the bet a little smaller and it becomes a call.

The working

  1. Range. The stated range is 80 combos. 24 of them use a card you can see (your hand or the board), which leaves 56.
  2. Equity. You win 31.7% and chop 0.1%, so equity is 31.7% + 0.1% ÷ 2 = 31.7%. Each hand class gets 20,000 sampled runouts with its own fixed seed, weighted by live combos. Sampling error is about ±0.12 points (one standard error).
  3. Price. Calling risks the bet to win the pot plus the bet, so break-even is bet ÷ (pot + 2 × bet) = 10 ÷ (10 + 2 × 10) = 33.3%.
  4. EV. equity × (pot + bet) − (1 − equity) × bet = 0.3170 × 20 − 0.6830 × 10 = −0.49 bb. Folding is 0, so that is the whole difference between the two options.

Where the equity comes from

Your equity against every hand class in the range, with how much of the range each one is. The total above is these rows averaged by combo count.

VillainCombosShareWinChopYour equity
2235.4%25.6%0.0%25.6%
7735.4%25.9%0.0%25.9%
JTs35.4%27.7%0.0%27.7%
JTo916.1%28.6%0.0%28.6%
T9s23.6%29.2%2.1%30.2%
QTs35.4%32.7%0.0%32.7%
ATs35.4%32.8%0.0%32.8%
KTs35.4%33.6%0.0%33.6%
QTo916.1%33.8%0.0%33.8%
KTo916.1%33.9%0.0%33.9%
ATo916.1%34.8%0.0%34.8%
// settle the thread

The link encodes the whole spot. Anyone who opens it gets these numbers, recomputed in their own browser.

Disagree with the range, or want to see where the answer flips? Open this spot in the calculator and change anything: cards, bet size, villain range.

Change the numbers →
// what is computed, and what is assumed
  • Computed: card removal, equity (exact on the river, sampled with fixed seeds before it), the break-even price, and the EV of calling. Same engine, same seeds, same numbers for anyone who opens the link.
  • Assumed: the range. Villain bets every combo in it, all equally often. The four archetype ranges are our assumptions and are printed in full; a pasted range is yours.
  • Assumed: this is the last bet. Before the river, the EV counts you as seeing every remaining card with no more money going in. That is exact when the bet is all-in (every worked example below is) and optimistic otherwise, because it ignores implied odds and reverse implied odds alike.
  • Pot is everything in the middle except the bet you face; bet is what it costs you to call. Range notation: AA, AKs, AKo, AK (both), TT+, ATs+, 22-55, A2s-A5s. No weights or single combos.

More worked spots

Flop, facing an all-in