AF

Overview

AF stands for Aggression Factor, a common HUD (Heads-Up Display) statistic used in online poker to quantify how aggressively a player plays postflop. It is derived from the formula:

AF = (Bets + Raises) / Calls

Only postflop actions (flop, turn, river) are considered; preflop actions and folds are excluded. A player who bets or raises frequently relative to calling will have a high AF, while a player who calls often will have a low AF.

Interpretation

• Low AF (e.g., < 1): The player calls more often than they bet or raise. This often indicates a passive or calling-station style. They may be chasing draws or unwilling to fold marginal hands.
• High AF (e.g., > 3): The player bets and raises frequently. This suggests an aggressive style, capable of bluffing and value-betting. However, extremely high AF (e.g., > 5) on a small sample may indicate a maniac or a player who rarely calls.
• Moderate AF (1–3): Common for balanced players who mix aggression with appropriate calls.

Practical Usage

AF is most useful in conjunction with other stats, such as VPIP (Voluntarily Put Money In Pot) and PFR (Preflop Raise). A player with a high VPIP but low AF is a loose-passive (calling station). A player with a low VPIP and high AF is a tight-aggressive (TAG) — often a strong opponent. A player with both high VPIP and high AF is a loose-aggressive (LAG), who can be dangerous but also exploitable.

AF by street (flop, turn, river) can reveal tendencies. For example, a player with high flop AF but low turn AF may be continuation-betting frequently but slowing down on later streets.

Limitations

• Sample Size: AF requires a decent number of hands (typically >100) to be reliable. A small sample may produce misleading extremes.
• Context: AF does not distinguish between value bets and bluffs. A player can have a high AF by bluffing too much or value-betting thin. It also ignores checking, which is a passive action but not counted as a call.
• Game Type: AF interpretation varies by game type (cash vs. tournaments) and player positions.

Alternatives

Some trackers offer Aggression Frequency (AFq), which calculates aggressive actions as a percentage of all actions (excluding folds). AFq = (Bets + Raises) / (Bets + Raises + Calls + Checks). This can be more intuitive than AF.