K/9 and BB/9
Description:
Strikeout Rate (K/9) and Walk Rate (BB/9) are rate statistics that measure how many strikeouts and walks a pitcher averages over nine innings. Of course, not many pitchers throw nine innings all at once anymore, but this is simply a way of standardizing the statistic so it’s on an easy-to-understand scale for more fans.
For pitchers, more strikeouts are obviously good, while walks are bad. Good pitchers normally strikeout at least twice as many batters as they walk.
Context:
2010 Strikeout and Walk Rates


Things to Remember:
- Average strikeout and walk rates have changed over baseball’s history. Right now, strikeout rates are at an all-time high.
- Some people prefer to measure pitcher strikeout and walk rates by using K% and BB%, since those account for the fact that some pitchers face more batters per inning than other pitchers (therefore, getting more chance to strike them out or walk them). Either form of strikeout and walk rates are acceptable.
Links for Further Reading:


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