Definition
Stack-to-Pot Ratio (SPR) is the ratio of the effective stack size to the pot size at the start of a street (usually the flop).
SPR = Effective Stack / Pot Size
Why SPR Matters
SPR determines:
- How much of your stack is at risk
- What hands can profitably commit
- Your strategic flexibility
Calculating SPR
Example 1: High SPR
Pot on flop: $20 Effective stacks: $200
SPR = 200 / 20 = 10
Example 2: Low SPR
Pot on flop: $100 Effective stacks: $150
SPR = 150 / 100 = 1.5
SPR Categories
| SPR | Category | Stack Commitment |
|---|---|---|
| < 3 | Very Low | Easy to commit |
| 3-6 | Low | One pair can commit |
| 6-13 | Medium | Need strong hands |
| 13+ | High | Need very strong hands |
What Hands Play Well at Different SPRs
Low SPR (< 4)
✅ Play well:
- Big pairs (AA, KK, QQ)
- Top pair
- Overpairs
❌ Play poorly:
- Drawing hands (not enough implied odds)
- Small pairs (can't set-mine effectively)
High SPR (> 10)
✅ Play well:
- Suited connectors
- Small pocket pairs
- Hands with nut potential
❌ Play poorly:
- One-pair hands (hard to stack off)
- Dominated hands
SPR Strategy Guide
| SPR | Strategy Focus |
|---|---|
| 1-2 | Get it in with top pair+ |
| 3-5 | Top pair is strong, sets are premium |
| 6-10 | Sets and two pair want action |
| 10+ | Need the nuts or near-nuts to stack |
Poker Examples
Low SPR Spot
You: A♠ K♥ Board: K♣ 7♦ 2♠ Pot: $100 | Stacks: $150 | SPR: 1.5
With SPR of 1.5, top pair top kicker is a monster. You can happily get all-in.
High SPR Spot
You: A♠ K♥ Board: K♣ 7♦ 2♠ Pot: $20 | Stacks: $300 | SPR: 15
With SPR of 15, you have top pair but can't easily stack off. Sets and two pair beat you, and there's lots of play left.
SPR and Preflop Sizing
You can manipulate SPR with preflop bet sizing:
| Want Low SPR | Want High SPR |
|---|---|
| Raise bigger | Raise smaller |
| 4-bet more | Just call 3-bets |
| Build the pot | Keep pot small |
Why Manipulate SPR?
| Hand Type | Preferred SPR |
|---|---|
| Big pairs | Low (easy decisions) |
| Suited connectors | High (implied odds) |
| Dominating hands | Low (commit stacks) |
Common Mistakes
| Mistake | Problem |
|---|---|
| Ignoring SPR | Playing all spots the same |
| Set-mining at low SPR | Not enough implied odds |
| Overpair at high SPR vs raise | Often beaten |
Key Takeaway
SPR shapes every postflop decision. Low SPR = big pairs dominate, commit easily. High SPR = need nut potential, one pair is vulnerable. Always check SPR before planning your hand.