Same hand, different stakes inside the pot
You flop top pair with a good kicker. In one hand, there’s $40 in the pot and the other player has $40 left. In another, the pot is still $40, but you can each put in $360 more. Your cards are identical. The decision you’re building toward is not.
Stack-to-pot ratio, or SPR, measures how much money can still go in relative to what’s already in the middle. It gives you a way to see whether one ordinary bet could put stacks at risk or whether several big decisions are still ahead. Use it to plan a hand, not to decide the hand by itself.
Use the smaller stack, and count what’s left
At the start of a street, divide the remaining effective stack by the pot. Heads-up, the effective stack is the smaller of the two stacks still behind. If you have $240 and your opponent has $80, with $40 in the pot, the SPR is $80 ÷ $40 = 2. Your other $160 can’t be matched by that opponent.
Count the pot before anyone bets on that street. Chips already in the middle go in the denominator, not in the remaining stack. Use the same units for both numbers: dollars, chips, or big blinds. A rough estimate is usually enough to tell the difference between an SPR near 1 and one near 8.
PokerStars Learn introduces SPR as a way to relate effective stacks to the pot. Andrew Brokos’s GTO Wizard analysis goes further: the ratio helps you measure the risk of committing a stack against the reward already available.
SPR = smaller remaining stack ÷ pot size, measured before the street’s first bet in a heads-up hand.
Watch what a called bet does to both numbers
Start the turn heads-up with $60 in the pot and $120 effective. SPR is 2. If you bet $30 and get called, the river pot is $120 and the remaining effective stack is $90. A river shove would be 75% of the pot.
Now try $60 on the same turn. If called, the river pot is $180 and only $60 remains. The shove is now one-third pot. The larger turn bet gets more money in early, but it may also cause weaker hands to fold before the river. The two lines don’t necessarily reach the last street against the same hands.
Those are planning examples, not recommended sizes. Before choosing either one, ask which hands can call on the turn and which can pay on different rivers. A tidy path to all-in has no value if the opponent can’t realistically take that path with hands you beat.
Low SPR makes a shove smaller, not automatically good
Suppose the pot is $40 on the flop and your opponent shoves the remaining $40. You’re calling $40 for a final pot of $120. Ignoring rake, you need one-third equity. If the remaining stack were $120 instead, calling the full shove would cost $120 for a $280 final pot, requiring about 43% equity.
Those are break-even prices, not estimates of how often your hand wins. If a player shoves mainly sets on a particular board, top pair can be a fold even at SPR 1. If the opponent shoves many draws or weaker made hands, the same top pair may have enough equity. Read the action and the board before using the price.
The useful difference: low SPR leaves less room for future pressure. Deep stacks can leave you facing a turn bet and a much larger river bet. With a medium hand, think about which turn cards let you continue and which ones make checking or folding more attractive.
Work backward when you want to build a big pot
Say you start the flop with a $20 pot and $70 effective. If you bet half pot on each street and get called, the sequence is $10 on the flop, $20 on the turn, and $40 on the river. The pot doubles after each called half-pot bet, and the three bets use exactly $70.
GTO Wizard calls a constant fraction that gets the stacks in on the last street geometric sizing. It’s a benchmark for how a pot can grow, not a schedule you have to follow. A draw completing, an unexpected raise, or a weaker calling range can make the next planned bet a poor choice. Likewise, a strong hand may want to collect more on an earlier street if many later cards could stop the action.
Try the same exercise with a hand you’d prefer to take to showdown cheaply. If your usual flop size leaves a turn decision you can’t justify against the likely callers, that’s a reason to reconsider the flop size or check.
Multiway: check who can match the next bet
With a $50 pot, your $300 stack may be up against one opponent with $50 left and another with $250. As a quick comparison to the current pot, that’s SPR 1 against the short stack and SPR 5 against the deeper one. The short player’s all-in doesn’t prevent you and the deeper player from putting more in a side pot.
Don’t plug those ratios into the heads-up shove example. An extra caller changes the pot, the hands you need to beat, and which chips you’re eligible to win. When action continues, work out the actual main pot and any side pot before judging your price. In a tournament, payout pressure can also make a chip-profitable decision unattractive in prize-money terms.
Take this to your next session
- At the flop, estimate the pot and the effective stack before looking for a bet size.
- Before betting, picture the next pot and remaining stack if your bet is called.
- If you’re planning for stacks, identify worse hands that can keep calling. Revisit the plan when the board or action changes.
- If you’re facing a shove, calculate the actual call price and compare it with your equity against a realistic range.
- Review one hand in two versions: the actual effective depth and twice that depth. Keep the cards and pot fixed, then explain what changes about your plan.