K/BB shows a pitcher’s number of strikeouts for each walk that they allow.
A higher K/BB indicates better pitching ability (as there are more strikeouts in relation to walks allowed).
It is the opposite of the Walk to Strikeout Ratio (BB/K) which is used to evaluate hitters.
K/BB = Strikeouts ÷ Walks
If a pitcher throws 143 strikeouts and in that time allows 64 walks, then:
K/BB = 143 ÷ 64
K/BB = 2.23
This pitcher’s K/BB is 2.23 – they pitch approximately 2.23 strikeouts for each walk they allow.