Effective Stack
The effective stack is the smallest stack among players in a hand: the most chips that can actually be won or lost between them.
The effective stack is the smaller of the stacks in a confrontation, because that is the most chips that can actually change hands. If you have 300 chips and your opponent has 80, the effective stack is 80. No matter how much you bet, you can only win or lose 80 against that player. Effective stacks drive almost every strategic decision about bet sizing, hand selection and when to go all-in.
How to calculate it
- Heads-up: the effective stack is simply the smaller stack.
- Multiway: look at each opponent separately. Your effective stack against a 60-chip player is 60, while against a 250-chip player it might be your own 200.
- In big blinds: players usually express effective stacks in big blinds. An effective stack of 80 chips in a 1/2 game is 40 big blinds.
- Mid-hand: after chips go in, use what is left behind. After a 15-chip preflop raise and call with 100-chip stacks, the effective stack on the flop is 85.
Why it matters
Your own stack size alone can mislead you. A big stack facing a short stack plays as if both players are short. Effective stacks shape strategy in several ways:
- Hand selection: speculative hands like small pairs and suited connectors need deep effective stacks to pay off through implied odds. When effective stacks are short, high-card strength matters more.
- Commitment: the stack-to-pot ratio is the effective stack divided by the pot. A low ratio means one-pair hands are often worth getting all-in.
- Bluffing power: deep effective stacks let you apply pressure over several streets. Short ones limit your fold equity.
Example hand
A 1/2 cash game. You have 400 chips on the button with 6♥ 5♥. The cutoff, who has only 40 chips (20 big blinds), raises to 6. Your big stack is irrelevant here: the effective stack is 40. Even if you hit a perfect flop like 7♣ 4♦ 3♠, the most you can win from the cutoff is the 40 they have. Calling 6 to win at most around 40 more is a poor price for a hand that rarely connects, so folding or, if the read is right, re-raising all-in are both more sensible than calling.
Now suppose the cutoff also has 400. The effective stack is 400 (200 big blinds), and 6♥ 5♥ becomes a reasonable call in position, because the payoff when you make a straight or two pair can be huge.
Later in a hand, effective stacks also tell you how to size bets: with 90 behind and 30 in the pot, a turn bet of about 30 and a river bet of 60 can get all the chips in naturally.
Quick tips
- Glance at the effective stack before every preflop decision, not just your own chips.
- In tournaments, think in big blinds; 15 big blinds effective calls for a very different strategy from 60.
Frequently asked questions
How do you find the effective stack?
Take the smaller of the two stacks involved. In multiway pots, compare your stack to each opponent's separately.
Why is effective stack more important than my own stack?
You can never win or lose more than the smaller stack against a given opponent, so that number defines the real stakes of the hand.
What is a deep effective stack?
Usually around 100 big blinds or more. Many players consider 150 big blinds and up to be deep.
Related poker terms
- SPR (Stack-to-Pot Ratio) — SPR (stack-to-pot ratio) is the effective stack divided by the pot on the flop. It shows how committed you are and which hands can play for stacks.
- Short Stack — A short stack is a chip stack that is small relative to the blinds, often under about 20 big blinds, leaving little room beyond shoving or folding.
- Deep Stack — A deep stack is a chip stack that is large relative to the blinds, often 150 big blinds or more, allowing more postflop play and bigger implied odds.
- Implied Odds — Implied odds count the extra chips you expect to win on later streets when you hit, making some calls profitable despite poor direct pot odds.
- All-In — Going all-in means betting every chip you have in front of you. You can't be forced out of the hand, but you can only win what your chips cover.