WHIP Explained: The Pitcher's On-Base Measure

By 4Baseball Staff · November 5, 2026 · 9 min read

WHIP is walks plus hits per inning pitched. Learn the formula, what a good number is in each era, where the statistic came from, how it compares with ERA, and the flaws that keep it from being the whole story.

WHIP stands for walks plus hits per inning pitched. You add the walks and hits a pitcher allows and divide by his innings, and the result is the average number of baserunners he puts on per inning. A pitcher with a WHIP of 1.00 allows one baserunner an inning. One at 1.50 allows a baserunner and a half. The lower the number, the better, and the best seasons in the historical record fall below 0.90.

The statistic is simple, and that is its appeal. It does not depend on how many runs scored, which means it is less affected than earned-run average by the sequencing of hits, the quality of the bullpen that finishes an inning, or a single bad inning. It asks one question: how often did this pitcher let a hitter reach base by a hit or a walk?

This article covers the formula with worked examples, the numbers that count as good in different eras, the history of the statistic, and the places it misleads. It uses the historical record, through the 2025 season, for every historical figure. For the sister measures that try to isolate a pitcher's skill, see the article on FIP, xFIP and SIERA.

The formula, with real examples

WHIP = (hits allowed + walks allowed) / innings pitched.

Innings are counted in thirds, since a pitcher records outs and not whole innings. A line reading 6.1 innings means six and one-third, which is 6.333 in the formula, and 6.2 means 6.667. Many websites print the box-score form (6.1) and calculate with the decimal form (6.333) behind the scenes, and the difference matters when you do the arithmetic by hand.

Here are three real seasons from the historical data, chosen to cover a wide range:

Take Gibson. He allowed 198 hits and 62 walks, a total of 260 baserunners, across 304� � innings. Dividing 260 by 304.667 gives 0.853. Martinez's 2000 season, in which he allowed 160 baserunners in 217 innings, is the lowest WHIP of any pitcher with at least 150 innings since 1901 in the historical record. Ryan's 1973, in which he struck out 383 hitters and walked 162, produced a much higher figure, and it shows what WHIP measures: Ryan's strikeouts, which were record-setting, do not appear in the formula at all.

WHIP also treats a walk and a single as the same event. That is the root of both its strengths and its weaknesses. Two pitchers can finish with identical WHIPs for different reasons. Take two hypothetical starters who each throw 180 innings. One allows 180 hits and 30 walks, the other allows 120 hits and 90 walks. Both score 210 baserunners over 180 innings, a WHIP of 1.167. The first throws strikes and leans on his fielders to turn balls in play into outs. The second is wild but hard to hit. WHIP cannot tell them apart.

Reading the number against the league

A good WHIP depends on the year. The league average has swung widely, and the historical team tables let us calculate it by adding up the hits and walks allowed by every club and dividing by every club's innings.

Look at the first two columns. In 1930, a year of huge scoring in both leagues, the average team allowed 1.521 baserunners an inning. In 1968, the Year of the Pitcher, it was 1.193. A WHIP of 1.30 was a poor season in 1968 and a good one in 1930. Whenever you compare WHIPs from different years, compare each to its own league.

A rough rule of thumb for recent years: a starter below 1.10 is excellent, 1.10 to 1.25 is good, 1.25 to 1.35 is about average, and above 1.45 is a pitcher who is struggling. Those bands are anchored to the league figures of 2014 to 2025, which sit between 1.275 and 1.334 in the table. Shift them up or down for a different run environment.

The last column is a bonus. Dividing the earned-run average by the WHIP gives nine times the earned runs per baserunner, so 3.24 means that about 36 of every 100 hits and walks (3.24 divided by 9) eventually came around as earned runs. In 1908 the figure was about 23 per 100, and in 2019 it was about 37. The change partly reflects the rise of the home run and the extra-base hit: a league that hits more doubles and homers converts more of its baserunners into runs. It is a reminder that WHIP counts baserunners and not damage.

Where WHIP came from

The statistic is a product of rotisserie baseball. The game began around 1980 among a group of friends in New York and needed pitching categories that rewarded more than wins. The measure is usually credited to the writer Daniel Okrent, one of the founders of the game. Rotisserie leagues adopted it alongside earned-run average, saves, wins and strikeouts as one of the standard pitching categories, and it spread to the fantasy platforms that followed.

The idea of counting baserunners was older than the acronym. Scorekeepers and writers had long noted how many men a pitcher allowed on base, and hits per nine innings and walks per nine innings were standard figures in the record books. WHIP combined them into one number.

Today WHIP is printed on the stat lines of the major sports sites, and the historical tables carry the ingredients, hits, walks and innings pitched, for every season. It is not an official statistic in the sense that the league office crowns a WHIP champion, but it is a calculation anyone can do from the box score.

The best WHIPs in history

Two lists are worth knowing. The first is the career list for pitchers with at least 1,000 innings, through the 2025 season.

Joss and Walsh pitched in the early 1900s, when the league WHIP was low. Rivera, a reliever, is a member of the list because his innings were exceptionally clean; the list includes relievers who reached 1,000 innings. The inclusion of a 1900s pitcher and a modern reliever shows why a career WHIP needs context. DeGrom and Kershaw are the modern starters at the top.

The second list is single seasons of 150 or more innings since 1901. Pedro Martinez in 2000 is first at 0.737, with Walter Johnson in 1913 second at 0.780 in 346 innings. Justin Verlander in 2019 is third at 0.803, Addie Joss in 1908 fourth at 0.806, and Greg Maddux in 1995 fifth at 0.811. Three of the top five come from 1995 or later, and two from the dead-ball years, the two eras in which pitchers held hitters off the bases best.

One more data point. In the historical record, 229 pitcher-seasons of 150 or more innings since 1901 had a WHIP under 1.00. Fifty of them came in the 1900s, 32 in the 1910s, only 11 across the 1920s through the 1950s, and 28 in the 1960s. The 1970s through the 2000s produced between 9 and 13 per decade, and then the count rose again: 36 in the 2010s and 26 in the six seasons of the 2020s through 2025. The sub-1.00 season was common in the dead-ball years, nearly disappeared for decades, and has returned.

What WHIP gets right

First, it is tied to scoring. A baserunner who is not on base cannot score, and a pitcher who allows fewer baserunners has a lower floor on the runs against him. For that reason WHIP and ERA are correlated, and a pitcher with a very low WHIP and a high ERA is probably due for better results. This is the logic behind run expectancy: each baserunner changes the expected number of runs, which the article on run expectancy and the 24 base-out states quantifies.

Second, it is stable. A pitcher's ERA depends in part on whether runners come home, a function of what happens with runners on base and of the bullpen that inherits them. WHIP does not look at runs at all. It measures the front end of the process and not the back end.

Third, it is transparent. Anyone with a box score can compute it, and anyone can see what went into it. Many modern metrics are black boxes, which has its own cost.

What WHIP gets wrong

It treats all hits alike. A home run and a bunt single both add one to the numerator. A pitcher who gives up solo homers and one who gives up singles can post the same WHIP and different ERAs, as the ERA-divided-by-WHIP column above suggests. The conversion of baserunners into earned runs rose from about 23 per 100 in 1908 to about 37 per 100 in 2019, and WHIP sees none of that.

It treats a walk like a hit. Walks and hits are not equal in damage or in cause. A hit is partly the pitcher's doing and partly the defense's. A walk is almost entirely the pitcher's. A pitcher with a low hit rate and a high walk rate may be getting lucky on balls in play, and the WHIP blends the two together.

It ignores hit batters. A hit-by-pitch puts a runner on just as a walk does, but the formula leaves it out. Reaching on an error is also excluded, which is fair, since the pitcher is not charged, but the runner still counts against the team.

It lumps in intentional walks. A pitcher who walks a slugger on purpose has made a choice the formula cannot see.

It cannot see strikeouts. Ryan's 1973 season, 383 strikeouts, still produced a mediocre WHIP. A strikeout is the best outcome a pitcher can produce, since it removes the defense from the equation, and WHIP gives it no credit beyond the baserunner it prevented.

It ignores timing and sequence. Three baserunners in a single inning that end in three outs are not the same as three baserunners and a three-run homer. WHIP is blind to who is on base and how many outs there are, which is the territory of win probability and leverage.

It is noisy over short stretches. A reliever with 70 innings can swing 0.14 points in WHIP on ten extra hits. That is the difference between a good season and a bad one, and it is not a signal.

WHIP in fantasy baseball

In rotisserie and points leagues that use ratio categories, WHIP carries a special cost: it is a rate, so it weights each pitcher by his innings. A starter with 200 innings at 1.10 helps a team's WHIP far more than a reliever with 60 innings at 1.00. Because the category is a ratio, one blow-up start can undo several good ones, and managers who chase wins from weak starters pay for it in the ratios.

The practical advice is not complicated. Compare a pitcher's WHIP to his strikeout and walk rates, since a low WHIP built on a lucky rate of hits on balls in play tends to drift toward the average. Look at the walk rate first because it is the component the pitcher controls most. To check the arithmetic yourself, try the stat calculator, and see the fantasy pages for the rest of the season's tools.

Which measure for which question

No single pitching number is enough, and the right choice depends on the question. If you want to know what happened, ERA tells you the runs and WHIP tells you the baserunners; the ERA and ERA+ article shows how to adjust ERA for park and league. If you want to know what a pitcher can repeat, the fielding-independent measures such as FIP look at strikeouts, walks and home runs. And if you want to know how much a pitcher contributed to winning, the answer is WAR, covered in the WAR explanation.

WHIP sits in the middle. It is more informative than wins or saves, simpler than FIP, and easier to check than WAR.

Common questions

What is a good WHIP? It depends on the year. In the 2010s and 2020s, below 1.10 is excellent, and around 1.30 is the league average. In 1968 the league average was 1.193.

How do I convert innings with a decimal? The box-score notation uses .1 for one-third and .2 for two-thirds. Convert to 0.333 and 0.667 before dividing.

Does WHIP include hit batters? The standard version does not. It counts hits and walks only.

Who has the best career WHIP? Among pitchers with 1,000 or more innings, Addie Joss, at 0.97, through the 2025 season.

Is WHIP better than ERA? It answers a different question. WHIP counts baserunners and ERA counts earned runs, and each can mislead when used alone.

Where to go next

For the measures that try to isolate skill, read the FIP, xFIP and SIERA explanation, and for the run side of the ledger, the ERA and ERA+ article. The full leaderboards, including WHIP leaders in every season, are on the site's leaders pages.