effective-stack

Effective stack is the smaller chip count between the two players in a contest. It determines the most you can win or lose on a hand, and it is a key input to SPR.

Detailed Explanation

Example: you have 100bb, opponent has 50bb. Even though you have more chips, you can only win or lose 50bb on this hand (because the opponent can only put in 50bb when all-in). Effective stack = 50bb.

In multi-way pots, effective stack is computed pairwise:

• A 100bb, B 50bb, C 200bb
• A vs B effective stack = 50bb
• A vs C effective stack = 100bb
• B vs C effective stack = 50bb

When making decisions, look at the effective stack with the relevant opponent — not the others.

How effective stack influences strategy:

1. Determines SPR: effective stack / pot
2. Determines the commit threshold: low effective stack means low SPR and earlier commitment
3. Determines draw playability: shallow effective stacks kill set-mining and suited-connector implied odds
4. Determines bluff frequency: shallow effective stacks remove the room for multi-street bluffs

Common practical reads:

• Effective stack < 30bb: preflop play approaches short-stack mode (push/fold thinking), little postflop room
• Effective stack 100bb (standard cash): full preflop + three-street operation space
• Effective stack 200bb+ (deep): deep poker, top pair's relative value drops, strong combos rise

Common Use Cases

• Pre-game / pre-table evaluation: identify who has a similar stack to you and decide the primary contest target
• 3bet sizing: effective stack drives 3bet SPR design
• Set-mining decisions: short stacks kill set-mining (insufficient implied odds)
• Multi-way pots: assess effective stacks against each opponent independently to avoid being trapped by the deepest stack