Why is top pair a strong hand in a 4-bet pot and a dangerous one in a limped pot? Why do pros love small pairs deep-stacked and hate them short? The answer is one number: the stack-to-pot ratio, or SPR. It tells you, before you act on the flop, how many big bets are left in the hand — and therefore how strong your hand needs to be to get all the money in happily.
Key takeaways
- SPR = effective stack ÷ pot, measured at the start of the flop.
- Single-raised pots at 100bb have a high SPR (about 13–18); 3-bet pots about 4–6; 4-bet pots 1–2.
- Low SPR: top pair and overpairs are usually strong enough to commit.
- High SPR: one pair is rarely worth stacking off; sets, two pair and strong draws gain value.
- Plan your commitment on the flop instead of deciding on the river.
Calculating SPR
SPR = effective stack ÷ pot size on the flop
Use the effective stack (the smaller of the two stacks) and the pot as the flop comes down.
| Pot type (100bb stacks, 6-max) | Flop pot | Stacks left | SPR |
|---|---|---|---|
| Single-raised: BTN opens 2.5bb, BB calls | 5.5bb | 97.5bb | ~18 |
| Single-raised with a cold caller (CO opens, BTN calls) | 6.5bb | 97.5bb | ~15 |
| 3-bet pot: CO opens 2.5, BTN 3-bets to 8, CO calls | 17.5bb | 92bb | ~5 |
| 4-bet pot: open 2.5, 3-bet 8, 4-bet 20, call | 41.5bb | 80bb | ~2 |
(The pots include the dead small and big blinds where they folded.)
What SPR tells you
The lower the SPR, the fewer bets it takes to get all-in, and the weaker the hand you can commit with.
| SPR | Getting all-in takes… | Hands happy to commit |
|---|---|---|
| Under 3 | About one big bet | Top pair good kicker, overpairs, strong draws |
| 3–6 | Two bets | Strong top pair and overpairs usually; think about the board |
| 7–12 | Three bets | Two pair, sets, strong draws; top pair wants pot control |
| 13 and up | Three big bets or more | Very strong hands; one pair rarely |
This is why AK is so comfortable in a 4-bet pot: with an SPR near 2, hitting top pair means you’re happy to get it in. The same top pair in a 100bb single-raised pot, facing a flop bet, turn raise and river shove, is usually beaten.
Same hand, different SPR
No-Limit Hold'em · 6-max · 100bb
3-bet pot
Pot 17.5bb · SPR ~5
Q84- Hero has top pair, top kicker
- One pot-sized bet and a shove get it in — a comfortable commitment against a CO 3-bet calling range
Single-raised
Pot 6.5bb · SPR ~15
Q84- Same top pair, same kicker
- Bet for value, but if the opponent raises the flop and bets big on the turn, their range is mostly two pair and sets — be ready to slow down
SPR and hand types
- Small pairs and suited connectors want high SPR. They rarely flop anything, so they need big implied odds — deep stacks to win when they hit a set, straight or flush.
- Big pairs and big aces like low SPR. They make one-pair hands that are easy to commit with when the pot is already big.
- This is why 3-betting (which lowers the SPR) suits strong one-pair hands, and why calling raises with small pairs needs deep effective stacks.
Planning with SPR
Before you act on the flop, ask:
- What’s the SPR?
- Is my hand strong enough to get all-in at this SPR?
- If yes, plan sizes that get the stacks in by the river (see geometric sizing).
- If no, plan to keep the pot manageable — see Pot Control.
Deciding on the flop avoids the most expensive mistake in poker: drifting into a huge pot with a hand you’d never have planned to stack off with.
Commitment
You’re committed when the pot is so large compared with your remaining stack that folding is almost never right. If you have 20bb left and the pot is 60bb, calling off your stack needs only 20 ÷ 100 = 20% equity. So if you’re not prepared to call a shove later, think twice about putting in that last bet that leaves you with a tiny stack behind.
Next up: how bigger preflop pots change everything after the flop — Playing 3-Bet Pots.
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