What are the pot odds on a pot-sized bet?

One-card direct odds assume you fold after a miss and pay no further bets. Use by-the-river odds when this call guarantees both cards, such as an all-in or a guaranteed free river.

When the bet equals the pot, you risk 100 to win 200, which is 2-to-1. You now need to win a third of the time. No single draw gets there on the next card, so draws need big implied odds or a call that guarantees both cards.

Worked example: the pot is 100 on the flop and your opponent bets 100. You call 100 to win the 100 already there plus the 100 bet, 200 in total. 100 to win 200 is 2-to-1, and 100 divided by 300, the pot after your call, is 33.3%.

With stacks behind, a flush draw hits the turn 19.1% of the time, nowhere near 33.3%, and even a combo draw at 31.9% falls a little short. All-in on the flop is different: a flush draw at 35.0% just clears the price and an open-ender at 31.5% falls just short, so the two best common draws land on opposite sides of the line by a couple of points. A combo draw all-in at 54.1% calls with room to spare, and it is usually the one doing the shoving. On the turn a flush draw at 19.6% is nowhere near the price.

Quick tip: Pot-sized bet, 2-to-1, 33% equity needed. The other key number to memorize.