Preflop Bet Sizing Theory

Intermediate

Definition

Preflop bet sizing refers to how much you raise or re-raise before the flop. Proper sizing achieves your strategic goals while giving the right pot odds (or denying them).

Open Raise Sizing

Standard Open Sizes

Format Standard Size
Online 6-max 2.5BB
Online Full Ring 3BB
Live 3-4BB+
MTT (late stages) 2-2.2BB

Adjusting Open Size

Factor Size Up Size Down
Position EP LP
Player skill Weak opponents Strong opponents
Stack depth Deep Short
Limpers Add 1BB per limper -

Position-Based Sizing

Position Recommended
UTG/MP 2.5-3BB
CO 2.5BB
BTN 2-2.5BB
SB 3BB (vs BB only)

3-Bet Sizing

Standard 3-Bet Sizes

Position vs Open Sizing
IP 2.5BB 7-8BB (3x)
OOP 2.5BB 9-11BB (3.5-4x)

Why Larger OOP?

When OOP, you want:

  • Fewer callers
  • Bigger pot (compensates for positional disadvantage)
  • More fold equity

4-Bet Sizing

Situation Sizing
IP vs 3-bet 2.2-2.5x the 3-bet
OOP vs 3-bet 2.5-3x the 3-bet
Short stacks Just shove

Example

Open: 2.5BB 3-bet to: 8BB 4-bet to: 18-20BB

Squeeze Sizing

Callers Multiplier
1 caller 4x open
2 callers 5x open
3+ callers 5-6x open

Sizing Goals

Goal Sizing Approach
Maximize fold equity Larger
Induce calls Smaller
Deny equity Large enough to price out draws
Build pot Standard or slightly larger

Common Sizing Mistakes

Mistake Problem
Min-raising Gives everyone odds
Too large open Risk more, win same pot
Same size all positions Not optimized
Tiny 3-bets Get called too often

Sizing as Information

⚠️ Your sizing gives information:

Pattern What It Reveals
Big = strong Exploitable
Small = weak Exploitable
Consistent Harder to read

Keep sizing consistent regardless of hand strength.

Key Takeaway

Preflop sizing should be position-aware and strategic. Standard opens are 2.5-3BB, 3-bets are 3-4x the open (larger OOP), and always add for limpers. Keep sizing consistent to avoid giving away information.

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