Effective Stack

Also known as: Effective Stacks

The smaller of the two stacks in a pot — the most you can actually win or lose. It drives **SPR** and every stack-depth decision.

Definition

The effective stack is the smaller of the two stacks involved in a pot. Because no one can win more chips than they have in front of them, the short stack caps how much money is genuinely in play — it is the most you can win and the most you can lose.

\[ \text{effective stack} = \min(\text{your stack},\ \text{their stack}) \]

Why it matters

Every depth-based decision runs off the effective stack, not your raw chips. It sets the SPR and your stack-to-blind ratio, which in turn fix sizing, commitment and whether a board is playable deep or fits a short-stack all-in plan.

Multiway

In a multiway pot the effective stack is measured separately against each opponent — you may be 200bb effective vs one player and 25bb effective vs another in the very same hand. Plan each matchup on its own number.