Strikeout-to-walk Ratio (K/BB)

Definition

K/BB ratio tells us how many strikeouts a pitcher records for each walk he allows. The number is found simply by dividing a pitcher's total number of strikeouts by his total number of walks. It's an essential tool for evaluating pitchers.

Strikeouts and walks are both known as "true outcomes" because they aren't affected by anything other than the pitcher and the batter. (Of course, that's in an ideal world. Obviously, the umpire and the catcher's pitch-framing ability have an impact as well.) To a pitcher, strikeouts, of course, are good, and walks are bad, so it offers a perfect juxtaposition for a ratio-based statistic.

K/BB ratio tells us a story that strikeouts and walks by themselves do not. Many power pitchers record a high number of strikeouts but, because they walk their fair share of hitters in the process, aren't very successful. Conversely, many finesse pitchers don't strike out a great deal of hitters but, because they have such pinpoint control, are successful.

Example

Watch: Danny Salazar strikes out seven and walks two in a start, affecting his strikeout-to-walk ratio.

Fantasy advantage

Strikeout-to-walk ratio often is used to portend a pitcher's future performance (or a hitter's, to a lesser extent, if one were to look at BB/K ratio). Strikeouts and walks are unaffected by defense and therefore considered more predictive of future performance than outcomes influenced by external factors.

In A Call

"K's per walk," "strikeouts per walk," "strikeout-to-walk ratio," "strikeouts vs. walks ratio"