Moneyball Monday 5/6 - Pitching Metrics

This week, I will introduce some pitching metrics that are becoming well known.

WHIP – Walks and Hits per Innings Pitched

WHIP keeps tracks of the walks and hits a pitcher gives up. This statistic represents how effective a pitcher does of keeping runners off the bases.

WHIP = Walks + Strikes ÷ innings pitched

FIP – Fielding Independent Pitching

FIP measures events that only a pitcher has control over like strikeouts, walks, hit by pitches, and home runs. This does not measure balls in play. This is useful for evaluating how efficient a pitcher is on outcomes that don’t result in a hit. It's also useful for predicting a pitcher's future results, because a pitcher has little control over what happens once the ball is put in play behind him.

FIP = ((HR x 13) + (3 x (BB + HBP)) - (2 x K)) ÷ IP + FIP constant. FIP Constant is the league/conference ERA

K/9 – Strikeouts per 9 innings pitched

K/9 evaluates the average number of batters a pitcher strikeouts over 9 innings. This is one metric used to evaluate how good a pitcher’s ability to strikeout batters is.

K/9 = (Strikeouts*9) ÷ Innings Pitched

BB/9 – Walks per 9 innings pitched

This is very similar to K/9 instead it evaluates walks. This metric shows how much a pitcher walks batters over time. This metric shows how a pitcher controls the ball, if a pitcher has a high BB/9 then he lacks control as he allows a lot of walks.

BB/9 = (Walks*9) ÷ Innings Pitched

HR/9

This is another metric to show how frequently a pitcher gives up home runs per nine innings.

HR/9 = (Home runs*9) ÷ Innings Pitched

K/BB – Strikeout to Walk Ratio

The K/BB ratio is a stat that evaluates how many strikeouts a pitcher records for each walk allowed.

K/BB = Strikeouts ÷ Walks

SIERA – Skill-Interactive Earned Run Average

SIERA is a stat that looks at a pitcher’s performance by eliminating factors that the pitcher can’t control. SIERA factors in balls in play and adjusts for the type of ball in play.

SIERA = 6.145 - 16.986*(Strikeouts/Plate Appearances) + 11.434*(Walks/Plate Appearances) - 1.858*((Groundball-Flyball-Popups)/Plate appearances) + 7.653*((Strikeouts/plate appearances)^2) +/- 6.664*(((Groundball-flyball-popups)/plate appearances)^2) + 10.130*(strikeouts/plate appearances)*((groundball-flyball-popups)/plate appearances) - 5.195*(walks/plate appearances)*((groundball-flyball-popup)/plate appearance)

Hopefully this informed you on some stats to help evaluate pitchers. Feel free to contact us with any questions. Stay tuned next week as we explore another topic.