Stack-to-Pot Ratio (SPR) and Commitment

Level 4 Strategy 3 min readLesson 3 of 11

Stack-to-Pot Ratio (SPR) and Commitment

What stack-to-pot ratio is, how to calculate it on the flop, and how SPR tells you which hands are strong enough to get all-in in single-raised, 3-bet and 4-bet pots.

By PokerLevelUp Team, 28 September 2026

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

Hero (BTN)AQ

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.