SPR
Stack-to-pot ratio: stack ÷ pot at the flop. Low SPR means commitment; high SPR rewards implied odds and skill.
Take a 1/2 game, 200 effective. Button opens to 8, big blind calls, and the flop pot is 17: 8 from each player plus the folded small blind's dead dollar. That leaves 192 behind, so SPR sits around 11. Room to maneuver. Same seat, same open, but this time the big blind three-bets to 30 with AK and the button flats JJ. Now the pot is 61, stacks behind are 170, and SPR is near 2.8. At that ratio a pot-size bet and a raise puts both players all in, so an overpair or top pair is a stack-off hand the moment chips start moving. Nothing left to fold to.
SPR tells you how many bets are left to fight over before someone's stack runs dry. Low SPR strips the hand down to raw strength: nobody folds a big pair with only a couple of pot-size bets behind it. High SPR pays off patience and disguise: suited connectors, small pairs hunting a set, and draws all gain value, because there's enough behind to get paid when you hit and enough room to fold cheap when you miss.
Rough bands help. Under about 3, it's commitment poker: top pair with a strong kicker or an overpair is going in, and pretending otherwise just donates a street of value. Four to six is the awkward zone: one pair is too much hand to abandon and not enough to stack off, which is where disciplined players win small pots and undisciplined ones lose big ones. Past 10, one pair wins small pots and loses big ones by default; stacks only move when sets, straights and flushes collide, so the hands that can make them quietly take over the game.
The ratio isn't weather: you set it before the flop. Three-bet AK or QQ and the pot swells while the stacks shrink: SPR lands near 3, exactly where one big pair plays itself. Flat-call 6-6 instead and SPR stays high, where the hand is worth little until it spikes a set and worth stacks when it does. Buying in short tilts the whole game the same way: at 40 big blinds a single-raised pot arrives around SPR 7 and any three-bet pot near 1.5, which is why short-stack poker feels so simple. One bookkeeping habit: SPR runs off the effective stack, the shorter one: that's all the money that can actually move.
The common leak is treating every strong hand the same regardless of SPR. Stacking off an overpair at SPR 11 because it "never folds preflop" ignores that deep stacks let opponents keep peeling with hands that pass you by the river: sets, two pair, straights that only turn up on later streets. Check the ratio before you commit chips, not after they're already in the middle.
SPR by preflop line
SPR is decided before the flop, not on it. These are the six lines you meet most often in a 6-max game with 0.5/1 blinds, priced in big blinds, same flop, six different games.
| Preflop line | Flop pot | Behind | SPR | What it means |
|---|---|---|---|---|
| Limped pot, 100bb | 2.5 | 99 | 40 | Nothing is committed. Sets, straights and flushes are worth stacks; one pair wins a small pot or loses a big one. |
| Single raise called, 100bb | 5.5 | 97.5 | 18 | The standard flop. Three streets of betting still fit, so position and hand reading do the work. |
| 3-bet pot, 100bb | 20.5 | 90 | 4.4 | Two pot-size bets and the stacks are gone. An overpair or top pair with a good kicker is a stack-off hand. |
| 4-bet pot, 100bb | 44.5 | 78 | 1.8 | Commitment poker. One bet puts it in, and folding after calling preflop is close to impossible. |
| Single raise called, 40bb | 5.5 | 37.5 | 6.8 | Short stack, single raised: one pair plays itself by the turn. Much simpler than the same line 100bb deep. |
| 3-bet pot, 40bb | 18.5 | 31 | 1.7 | Effectively preflop all-in. If you 3-bet at this depth, plan to get the money in. |
SPR always runs off the effective stack (the shorter one) because that is all the money that can move. The flop pot includes the small blind's dead half when it folds.
Practice spots
Real hands where this term decides the play.