A pitching statistic that is one of the primary metrics used to gauge pitchers and is the average number of strikeouts a pitcher has per nine innings of work. The figure it deduced by multiplying his strikeout quantity by nine, and then dividing that by how many innings he has pitched.
This is also known as "strikeout rate" or "strikeouts per nine innings."
This is a useful stat in analyzing a pitcher's ability to get guys out without allowing any contact. This can be especially useful for relief pitchers that come in with guys on base. Very few pitchers actually throw a full nine innings, but it's just a standardized way for fans to understand the importance of the strikeout. Obviously, as a pitcher, more strikeouts are a good thing. MLB's all-time king of this statistic for starters is retired pitcher Randy Johnson, whose K rate ended up at 10.6098. Only three players currently have a K rate in excess of 10, with the other two being Pedro Martinez (10.0398) and Kerry Wood (10.3432). The all-time relief leader is Rob Dibble, at 12.17.