WHIP in baseball stands for “walks and hits per innings pitched,” and is a direct measure of the rate at which a pitcher allows baserunners.
As the name implies, WHIP is calculated for a given period of time (usually a season or career) by adding up the number of walks and the number of hits a pitcher has allowed during that span, then dividing by the number of innings he pitched over the same timeframe.
The formula for calculating WHIP, then, is:
WHIP = (number of walks allowed + number of hits allowed)/(number of innings pitched)
Why Is WHIP Important?
The primary goal and purpose of any pitcher is to prevent batters from reaching base and, consequently, from scoring.
The rate at which a hurler allows baserunners, then, is a good baseline indicator of his performance over a period of time. And WHIP measures the two most prominent ways that a batter can reach base and that are directly within a pitcher’s control.
After all, within some variance in judgement calls on the part of umpires when it comes to determining balls and strikes and, to a lesser extent, distinguishing between hits and errors, it is the battle between pitcher and batter that determines whether an at-bat or plate appearance ends in a hit, a walk, or an out.
What Does WHIP Miss?
Since WHIP accounts for only walks and hits, it leaves out a few ways that a pitcher can be responsible for putting a batter on base.
Among those are …
- Hit batsmen (hit-by-pitch)
- Fielding error by the pitcher
- Fielder’s choice by the pitcher
Of those, only the hit-by-pitch is directly under a hurler’s control while pitching and represents a very small source of baserunners across the game.
What Is a Typical WHIP?
In the so-called Live Ball Era (starting in roughly 1920), the average WHIP has ranged from 1.193 (1968) to 1.509 (1936).
League leaders typically hover around the 1.000 mark, with some plunging well belo.