What Is WHIP?
WHIP stands for Walks plus Hits per Inning Pitched. It is a baseball statistic that measures the average number of baserunners a pitcher allows per inning. WHIP was invented by writer Daniel Okrent in 1979, who originally called it "Innings Pitched Ratio." It has since become one of the most widely used pitching statistics, appearing alongside ERA as a standard measure of pitcher effectiveness.
A lower WHIP indicates better performance, as it means fewer batters are reaching base against the pitcher. Elite pitchers maintain a WHIP below 1.00, meaning they average less than one baserunner per inning. The league average WHIP in Major League Baseball typically hovers around 1.30, though this varies by era and run environment.
WHIP Formula
The standard WHIP formula only counts walks (BB) and hits (H). Some analysts prefer an extended version that includes hit-by-pitch (HBP) since these also put runners on base. Note that innings pitched uses thirds: 6.1 IP means 6 and 1/3 innings, which equals 6.333 for calculation purposes.
WHIP Rating Scale
| WHIP Range | Rating | Description |
|---|---|---|
| Under 0.90 | Elite | Historically rare, Cy Young caliber |
| 0.90 – 1.05 | Excellent | All-Star quality pitcher |
| 1.05 – 1.20 | Above Average | Solid starter or top reliever |
| 1.20 – 1.35 | Average | League-average pitcher |
| 1.35 – 1.50 | Below Average | Back-end starter or middle reliever |
| Over 1.50 | Poor | Struggling or replacement-level |
Historical WHIP Leaders
The all-time single-season WHIP record belongs to Pedro Martinez, who posted a remarkable 0.737 WHIP in 2000 with the Boston Red Sox. Among career leaders, Addie Joss holds the record at 0.968 WHIP over his career (1902-1910), though modern-era pitchers like Mariano Rivera (1.000) and Clayton Kershaw (around 1.00) rank among the best ever.
For comparison, consider that a WHIP of 1.00 means exactly one baserunner per inning on average. Over a 9-inning game, that is 9 baserunners. A WHIP of 1.30 means roughly 12 baserunners per complete game, while a 0.80 WHIP allows only about 7 baserunners per 9 innings.
Limitations of WHIP
- Ignores type of hit: WHIP treats singles and home runs equally, though a home run is far more damaging
- Excludes errors: Runners who reach base on errors are not counted, even though they affect run scoring
- No context for timing: A walk with the bases empty is less harmful than a walk with bases loaded, but WHIP treats them the same
- Doesn't account for strikeouts: A pitcher who walks many batters but strikes out even more can still have a high WHIP despite being effective
- Hit-by-pitch exclusion: Standard WHIP ignores HBP, which also puts runners on base. The extended WHIP+ addresses this
Frequently Asked Questions
What is a good WHIP for a starting pitcher?
A WHIP below 1.20 is considered good for a starting pitcher. Anything below 1.00 is exceptional and typically seen only among the league's best arms. Most quality starters fall in the 1.10-1.25 range. Relief pitchers, who face fewer batters and pitch in shorter stints, often have lower WHIPs than starters, with elite closers regularly posting WHIPs below 1.00.
How does WHIP relate to ERA?
WHIP and ERA are correlated but measure different things. ERA measures runs allowed per 9 innings, while WHIP measures baserunners per inning. A pitcher can have a low WHIP but high ERA if the baserunners they allow frequently score (such as giving up many extra-base hits). Conversely, a pitcher with a higher WHIP might have a lower ERA if they strand a high percentage of baserunners. Using both metrics together provides a more complete picture of pitcher performance.
How do you handle partial innings in WHIP calculation?
Baseball records partial innings in thirds. An innings-pitched value of 6.1 means 6 and 1/3 innings (6.333), and 6.2 means 6 and 2/3 innings (6.667). This calculator accepts decimal input, so enter 6.33 for 6.1 IP or 6.67 for 6.2 IP to get accurate results. This distinction matters especially for relievers who may pitch only fractions of an inning.