AF from SB

Definition and Context

AF stands for Aggression Factor, a fundamental poker statistic that measures a player's tendency to bet or raise versus call. It is calculated as (Bets + Raises) / Calls. A higher AF (typically above 1.5) indicates a more aggressive style, while a lower AF suggests a passive approach. When applied to the small blind (SB) position — denoted as "AF from SB" — it isolates a player's aggression specifically from that seat, which is unique because the SB is a forced bet that often plays post-flop out of position.

Importance in Strategy

AF from SB is useful for understanding how a player handles the disadvantage of being out of position after the flop. A high AF from SB may indicate that the player frequently raises pre-flop to steal blinds or aggressively squeezes from the SB, compensating for positional weakness with aggression. Conversely, a low AF might suggest a player who prefers to limp-call or check-call from the SB, relying on deception rather than aggression.

How It Is Measured

The statistic is typically tracked by poker tracking software (e.g., PokerTracker, Hold'em Manager) and reported as a decimal. For example, an AF from SB of 2.5 means the player makes 2.5 aggressive actions (bet or raise) for every call when in the small blind. It is important to consider sample size — a small number of hands can produce misleading AF values. Minimum 50–100 hands from SB is recommended for meaningful analysis.

Limitations

AF from SB does not account for the strength of the player's holdings or the specific board texture. A high AF could result from either a habit of continuation betting with weak hands or from consistently strong starting hands. Additionally, the calculation excludes checks and folds, which can inflate AF for tight players. It should be used alongside other stats like VPIP (Voluntarily Put Money In Pot) and PFR (Pre-Flop Raise) from SB for a complete picture.

Practical Application

When facing an opponent with a known AF from SB, you can adjust your strategy. Against a high-AF SB, consider trapping with strong hands, as they are likely to bet for you. Against a low-AF SB, you can apply aggressive continuation bets, expecting them to fold often without a strong hand. However, these adjustments should be tempered by other factors like stack sizes, table dynamics, and opponent tendencies.

Conclusion

AF from SB is a specialized statistic that gives insight into a player's aggression pattern from a particular position. While not a standalone decision-making tool, it is a valuable component of a comprehensive player profile, helping to identify exploitable tendencies in small blind play.