The important words are remaining, effective, and at a stated moment. Starting with 100bb does not mean using 100 as the numerator after you have put chips in preflop. Nor does a 200bb stack mean that you can win 200bb from an opponent with only 40bb left. GTO Wizard's SPR explanation frames the ratio as risk relative to reward; the original ledgers below show exactly where each input comes from.
What SPR Measures—and What It Leaves Out
The common reference point is the start of the flop, after preflop betting is complete and before anyone makes a flop bet. At that point, divide the smaller remaining stack in a heads-up pot by the entire pot. Count the chips, not the number of players who are still interested in them. A folded player's contribution remains in the denominator.
Two hands can have identical SPRs and very different strategic problems. A pot of 10bb with 40bb behind and a pot of 50bb with 200bb behind both have SPR 4. Their absolute sizes differ. More importantly, the players may have reached those pots with different ranges, positions, and boards. The ratio captures none of that information. It is one field in the hand history, not a replacement for the hand history.
Think of SPR as a scale for pot growth. A remaining stack that is small relative to the pot can go in with fewer large betting steps. A stack that is many times the pot requires more growth, larger bets, or raises to get all-in. That observation helps you plan a line, but it does not establish whether building that pot is desirable with your hand.
Effective Stack Is Not Your Own Stack in Isolation
Suppose you have 160bb left and your only opponent has 60bb left. The remaining effective stack is 60bb: that is the amount either player can still lose to the other. If the pot is 20bb, the heads-up SPR is 3, not 8. Your extra 100bb cannot be matched by this opponent. This explanation concerns the chips that can still be contested, not the sum of both players' stacks.
Use one unit throughout. You can divide dollars by dollars or big blinds by big blinds; the ratio is the same. Mixing a stack recorded in dollars with a pot recorded in big blinds produces a meaningless number. Also distinguish bb, a quantity of big blinds, from BB, the big-blind seat. In the examples below, “BB adds 10bb” means the player in the big blind contributes another ten big blinds.
The ledgers use a six-max No-Limit Hold'em cash-game model with blinds of 0.5bb and 1bb. Every player starts with 100bb before posting. There are no antes, straddles, rake, jackpot deductions, or uncalled wagers. All players other than the button, small blind, and big blind fold before contributing anything. The small blind folds in each example, leaving 0.5bb of dead money. These are teaching lines, not recommended preflop sizes or ranges.
Example 1: A Single-Raised Pot
The button opens to 3bb, the small blind folds, and the big blind calls. “Calls 3bb” would be ambiguous: the big blind already posted 1bb, so the call adds only 2bb. Both active players finish preflop with 3bb invested and 97bb remaining. The folded small blind's 0.5bb stays in the pot.
| Event | Added now | Pot after event | BTN remaining | BB remaining |
|---|---|---|---|---|
| SB posts; BB posts | 0.5bb + 1bb | 1.5bb | 100bb | 99bb |
| BTN raises to 3bb | 3bb | 4.5bb | 97bb | 99bb |
| SB folds | 0bb | 4.5bb | 97bb | 99bb |
| BB calls to 3bb total | 2bb | 6.5bb | 97bb | 97bb |
| Flop, before any bet | 0bb | 6.5bb | 97bb | 97bb |
The flop SPR is 97 ÷ 6.5 = 14.923…, or approximately 14.92. You can check the denominator independently: 3 + 3 + 0.5 = 6.5bb. This second route to the total catches a common mistake: adding the big blind's original 1bb again after already counting its final 3bb contribution.
A relatively high ratio does not require passive play. It tells you that a full remaining stack is much larger than the current pot. Before choosing a line that could put all 97bb at risk, consider which strong hands both ranges can contain, how the board can change, and whether your hand benefits from a large pot. The ratio supplies the scale; the ranges supply the decision.
Example 2: The Same Starting Stacks in a 3-Bet Pot
Reset the hand: everyone starts with 100bb again. The button opens to 3bb, the small blind folds, and the big blind 3-bets to 11bb. The button calls. The big blind adds 10bb to its posted 1bb; the button adds 8bb to its earlier 3bb. Do not add eleven and three again as if they were fresh contributions.
| Event | Added now | Pot after event | BTN remaining | BB remaining |
|---|---|---|---|---|
| SB posts; BB posts | 0.5bb + 1bb | 1.5bb | 100bb | 99bb |
| BTN raises to 3bb | 3bb | 4.5bb | 97bb | 99bb |
| SB folds | 0bb | 4.5bb | 97bb | 99bb |
| BB 3-bets to 11bb | 10bb | 14.5bb | 97bb | 89bb |
| BTN calls to 11bb total | 8bb | 22.5bb | 89bb | 89bb |
| Flop, before any bet | 0bb | 22.5bb | 89bb | 89bb |
Now the flop SPR is 89 ÷ 22.5 = 3.955…, or approximately 3.96. The independent pot check is 11 + 11 + 0.5 = 22.5bb. The starting stacks have not changed, but the preflop action leaves less money behind and more money in the middle. Both changes lower SPR.
The action also changes the range problem. A button that calls a 3-bet need not hold the same distribution as a big blind that calls a button open. You cannot transfer a single-raised-pot recommendation just by noticing the same board. For the raise sequence itself, see the 3-bet poker guide; this article follows the resulting stack and pot.
Example 3: The Same Starting Stacks in a 4-Bet Pot
Reset once more to 100bb each. BTN opens to 3bb, SB folds, BB 3-bets to 11bb, BTN 4-bets to 25bb, and BB calls. BTN's 4-bet adds 22bb because BTN has already invested 3bb. BB's final call adds 14bb because BB has already invested 11bb. Both players reach the flop with 75bb behind.
| Event | Added now | Pot after event | BTN remaining | BB remaining |
|---|---|---|---|---|
| SB posts; BB posts | 0.5bb + 1bb | 1.5bb | 100bb | 99bb |
| BTN raises to 3bb | 3bb | 4.5bb | 97bb | 99bb |
| SB folds | 0bb | 4.5bb | 97bb | 99bb |
| BB 3-bets to 11bb | 10bb | 14.5bb | 97bb | 89bb |
| BTN 4-bets to 25bb | 22bb | 36.5bb | 75bb | 89bb |
| BB calls to 25bb total | 14bb | 50.5bb | 75bb | 75bb |
| Flop, before any bet | 0bb | 50.5bb | 75bb | 75bb |
The flop SPR is 75 ÷ 50.5 = 1.485…, or approximately 1.49. Check the pot with final contributions: 25 + 25 + 0.5 = 50.5bb. The name “4-bet pot” does not itself determine SPR. Smaller starting stacks, another raise size, dead money, or an ante would change the inputs.
| Same 100bb starting stacks | Each active player's total preflop contribution | Each active player's remainder | Flop pot | Flop SPR |
|---|---|---|---|---|
| Single raise to 3bb and call | 3bb | 97bb | 6.5bb | 14.92 |
| 3-bet to 11bb and call | 11bb | 89bb | 22.5bb | 3.96 |
| 4-bet to 25bb and call | 25bb | 75bb | 50.5bb | 1.49 |
Measure at the Same Moment
In the single-raised example, the flop opens with 6.5bb in the pot and 97bb behind. Suppose BB checks, BTN bets 2bb, and BB calls 2bb. The turn starts with a 10.5bb pot and 95bb effective, so the turn ratio is 95 ÷ 10.5 ≈ 9.05. That is a valid new snapshot. It is not a correction to the original flop SPR of 14.92.
The state while a bet is outstanding needs a label too. Immediately after BTN bets 2bb, the chips in the middle total 8.5bb, BTN has 95bb, and BB still has 97bb. Some hand displays or study discussions report the street-start ratio; others update the pot as actions occur. State your convention before comparing numbers. Calling a flop “SPR 14.92” and then comparing it with another hand measured after a bet creates a timing mismatch.
Do not use SPR as the pot-odds formula when facing a wager. If BTN bets 2bb into 6.5bb, BB's call costs 2bb and creates a final pot of 10.5bb. With no future betting and no rake, the break-even equity for that call is 2 ÷ 10.5 ≈ 19.05%. The stack-to-pot ratio answers a different question: how much remains behind relative to the pot. Neither number supplies the opponent's range.
For a hand review, record at least the start-of-street pot, both remaining stacks, each action's added amount, and the pot after that action. This makes it possible to reconstruct a calculation even when the platform's hand history uses “raise to” while your notes use “raise by.” A remembered SPR without its action record is much harder to audit.
How Position and Ranges Change the Meaning
Position changes the information available when you act. A player who acts last can observe checks or bets before choosing a response; an out-of-position player often must choose first. That difference is still present at SPR 2, 4, or 15. The poker positions guide covers the action order; attach that position information to the ratio instead of treating SPR as a position-free strategy.
Solve For Why explains how remaining stacks constrain future betting in English, with English captions. Use this excerpt as a planning illustration, not a fixed number of bets or an automatic all-in rule; position, ranges and future action still matter.
Ranges matter in a similarly concrete way. Ask whether the opponent can arrive with overpairs, sets, two pair, strong draws, or weaker pairs; then ask which of those hands would take the action you face. “I have top pair at low SPR” leaves out the part of the analysis that can change the answer. A strong hand against a wide betting range may be weak against a much narrower raising range.
Board texture changes the comparison as well. One pair on A♣7♦2♠ is not the same holding as one pair on J♠T♠9♦. The connected board admits different straights, two-pair combinations, and draws. Even within one texture, exact cards matter: holding a relevant suit or rank removes some opposing combinations. Use the poker ranges worksheet to separate possible hands from the weights assigned to them.
This is why “low,” “medium,” and “high” are descriptions, not rules of poker. SplitSuit's SPR guide presents coaching zones for commitment; those are a strategic framework, not a requirement to put in a stack with a named hand class. Here, the actionable task is to calculate the ratio correctly and test the proposed commitment against the actual situation.
Low SPR Does Not Automatically Mean All-In
Consider an original, deliberately simplified river test. The pot is 50bb and both players have 75bb left: SPR 1.5. The opponent shoves 75bb. Calling costs 75bb and makes the final pot 200bb, so a call needs 75 ÷ 200 = 37.5% equity before rake. That threshold says nothing about whether your hand actually has 37.5% against this opponent's shoving range.
On K♠Q♠J♠9♠2♦, suppose you hold A♥K♦. You have one pair, kings. For this test only, assign the opponent a range containing only made flushes, all of which beat you, with no bluffs, ties, or weaker value hands. The river is complete, so your equity against that stipulated range is zero. Calling loses the additional 75bb; folding loses no additional chips. The low SPR does not rescue the call.
That is a counterexample, not a claim that a real opponent always has a flush. If you add bluffs or worse value hands, you must recalculate your equity using their weights. The lesson is that the ratio fixes the wager's scale, while the range assumption fixes your chance of winning. Confusing those inputs is how a helpful planning tool becomes a mechanical stack-off rule.
Nor does having invested a large part of a starting stack prove that the rest must follow. Earlier contributions are already in the pot. The current decision compares the additional risk with the outcomes available now. A prior mistake can leave an awkward SPR; putting in more chips solely to defend that earlier choice does not correct it.
Multiway Pots and Unequal Stacks
Heads-up, a single smaller remaining stack is easy to identify. Multiway, one number can hide several relationships. In a separate teaching hand, BTN starts with 100bb, SB with 40bb, and BB with 150bb. BTN opens to 3bb and both blinds call to 3bb total. With no rake or ante, the flop pot is 9bb—not 9.5bb, because the small blind is active and its posted 0.5bb is already part of its 3bb contribution.
BTN has 97bb left, SB 37bb, and BB 147bb. Relative to the shared 9bb pot, BTN's remaining effective stack against SB is 37bb, giving 37 ÷ 9 ≈ 4.11. Against BB, BTN can contest another 97bb, giving 97 ÷ 9 ≈ 10.78. Reporting only “SPR 4.11” hides the deeper contest with BB. Reporting only “SPR 10.78” hides SB's much shorter stack.
| Relationship at this flop | Remaining stacks | Pairwise effective stack | Shared pot used for this snapshot | Descriptive ratio |
|---|---|---|---|---|
| BTN versus SB | 97bb / 37bb | 37bb | 9bb | 4.11 |
| BTN versus BB | 97bb / 147bb | 97bb | 9bb | 10.78 |
| SB versus BB | 37bb / 147bb | 37bb | 9bb | 4.11 |
These pairwise figures are descriptive snapshots, not three independent heads-up games. Everyone shares the same pot and can respond to the same actions. Once a short stack is all-in and side pots exist, identify which players are eligible for each pot and which remaining chips can enter it. PokerStars' Table Stakes and All-in and The Pot rules explain that the all-in player remains eligible for the part their chips cover, while only contributors can win a side pot. Do not add an opponent's unmatched excess to a pot you cannot win or pretend the shortest player's stack caps the deeper players' entire hand.
Account for Antes, Rake, and Dead Money Explicitly
The examples above omit deductions so their arithmetic stays visible. If your actual hand includes antes, folded callers, a straddle, or a rake deduction already taken from the displayed pot, use the actual recorded state. Do not silently carry a no-rake example into a different accounting convention. The stack and pot must describe the same moment under the same convention.
For a simple sensitivity test, take the first example's 97bb remaining stack and 6.5bb gross pot. If a hypothetical 0.5bb deduction has already left the pot, its net size is 6bb and the ratio becomes 97 ÷ 6 ≈ 16.17, not 14.92. This is not any room's rake schedule. It only shows how a changed denominator changes the result. If the hand history reports gross pots while your software reports net pots, explain that mismatch before comparing SPRs.
Likewise, add a hypothetical 1bb of total dead antes to the 6.5bb pot while holding the remaining effective stack fixed at 97bb. The ratio would be 97 ÷ 7.5 ≈ 12.93. Holding the remainder fixed is a modeling assumption: in a real hand, an ante paid by one of the active players may also change that player's remaining stack. Rebuild the ledger rather than adding an ante only to the denominator by habit.
A Stack-and-Pot Audit Checklist
| Possible error | What to check | Correction |
|---|---|---|
| Starting stack used after preflop | Did the active players already contribute? | Subtract their own contributions from their own starts. |
| Your deeper stack used heads-up | How much can the shorter opponent still match? | Use the smaller relevant remainder. |
| Blind counted twice | Does a raise-to total already include the blind? | Count added chips or final contributions, not a mixture. |
| Folded chips removed | Did a folded player contribute? | Keep their matched contribution in the pot. |
| Different timestamps compared | Was either figure measured after a bet? | Label the action state and compare like with like. |
| A multiway ratio treated as universal | Which players remain and who can win each pot? | Record pairwise stacks and any side pots. |
| Gross and net pot mixed | Has a deduction already left the pot? | Declare the convention and use the recorded amount. |
When you review a hand, write one compact sentence: “Before the flop bet, the pot is ___bb, the relevant remaining stacks are ___bb and ___bb, so SPR is ___.” Then write a second sentence naming position, board, and the opponent's assumed continuing range. Keeping those sentences separate makes it harder for an arithmetic fact to masquerade as a strategy conclusion.
If the result feels surprising, check the ledger before changing your strategy. A duplicated blind, a raise-to read as a raise-by, or the original 100bb stack left in the numerator can move the number substantially. Once the inputs are correct, ask what line you are evaluating and what can call, raise, or fold against it. SPR is most useful when it makes that next question more precise.
Sources and Example Boundaries
- GTO Wizard — “Stack-to-Pot Ratio”, November 17, 2022; reviewed October 28, 2026. The Overview and Equity and SPR sections support the definition and the distinction between risk, reward, and range-dependent equity. Its individual solver examples are not reproduced as universal instructions here.
- SplitSuit — “SPR Strategy and Concept in Poker”, reviewed October 28, 2026. The SPR Formula and What Does SPR Tell Me? sections provide another explanation of the metric and a coaching framework. This article does not adopt fixed commitment zones as rules.
- PokerStars — “The Rules of Poker”, reviewed October 28, 2026. Table Stakes and All-in and The Pot support main-pot and side-pot eligibility: a short all-in player cannot win later side-pot contributions, and only contributors can win that side pot.
All chip ledgers, ratios, the river counterexample, and the rake/ante sensitivity tests are original educational calculations with their assumptions stated above. They are not observed hands, measured player tendencies, a solver output, or a Poker-Eye performance test. Actual decisions still require the relevant rules, pot eligibility, ranges, and action history.
About the Editorial Team
The Poker-Eye Editorial Team researches, checks, and maintains product and educational content. Sources and product boundaries are reviewed before publication.