// spot check · preflop

Ace-king offsuit vs a nit’s 20 bb shove from the small blind

The Nit open-shoves 20 bb from the small blind; you are in the big blind. That is 21 bb in the middle with 19 to call, so the pot before the part you have to match is 2 bb.

Your hand
A♦K♣
Board
preflop
Facing
19 bb into 2 bb
Villain range: The Nit · 36 of 50 combos live
AA,KK,QQ,JJ,TT,AKs,AQs,AKo

Villain shoves The Nit’s range from /opponents: TT+, AQs+, AKo. That is far tighter than the solved 20 bb shoving range on the push/fold charts.

Fold−1.86 bb for calling
42.8% equity against 47.5% needed

What it shows

Against a range this tight even ace-king falls short of the 47.5% the price demands: two thirds of the range is a pocket pair, which has you at a coin flip or worse, and against AA and KK you are crushed. The solved 20 bb calling range assumes a much wider shover.

The working

  1. Range. The stated range is 50 combos. 14 of them use a card you can see (your hand or the board), which leaves 36.
  2. Equity. You win 30.5% and chop 24.6%, so equity is 30.5% + 24.6% ÷ 2 = 42.8%. Each hand class gets 20,000 sampled runouts with its own fixed seed, weighted by live combos. Sampling error is about ±0.13 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) = 19 ÷ (2 + 2 × 19) = 47.5%.
  4. EV. equity × (pot + bet) − (1 − equity) × bet = 0.4285 × 21 − 0.5715 × 19 = −1.86 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
AA38.3%6.1%1.4%6.8%
KK38.3%29.7%0.9%30.2%
TT616.7%42.7%0.4%42.9%
QQ616.7%43.0%0.5%43.2%
JJ616.7%43.1%0.4%43.3%
AKs25.6%2.3%90.6%47.6%
AKo719.4%1.6%96.8%50.0%
AQs38.3%67.8%4.5%70.0%
// 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.

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// 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