Walks per nine innings, abbreviated as BB/9, measures how many bases on balls a pitcher issues for every nine innings thrown.
It is a simple but telling stat that highlights a pitcher’s control and command of the strike zone.
Lower values usually indicate fewer free passes and greater efficiency on the mound, making BB/9 a useful tool for coaches, analysts, and fantasy managers alike across various games, eras, and competitive levels.
Walks per Nine Innings (BB/9) Calculator
Frequently Asked Questions
What is BB/9?
BB/9 represents the average number of walks a pitcher allows over nine innings.
It standardizes control performance across different workloads.
Why use nine innings for the calculation?
Nine innings equal a regulation game, making it a convenient baseline that allows easy comparison between pitchers with different inning totals.
Does BB/9 consider intentional walks?
Major League Baseball counts intentional walks in the official walk total, so they are included unless you manually remove them from your input.
Is a lower BB/9 always better?
Generally, yes.
Fewer walks mean fewer free baserunners.
However, context matters; some pitchers with high strikeout totals can tolerate a slightly higher BB/9.
How precise should innings pitched be entered?
Enter innings precisely, converting outs to decimal thirds.
For example, 7 innings and 2 outs become 7.2 innings.