What is FIP in Baseball?

What is FIP in Baseball? Read This First!

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Fielding Independent Pitching, or FIP, is among many new terms and acronyms used in modern baseball. It’s a statistic to judge pitchers’ performances based only on what he can control, and not on plays dependent upon fielders.

So, exactly what is FIP in baseball? Essentially, the FIP judges a pitcher based only on certain statistics: how many home runs, walks, and hit batsmen the pitcher allows, and how many strikeouts he recorded. The FIP tries to measure based only on things pitchers can control themselves ~ and ignores stats that involve other players on his team.

The goal is to discover a pitcher’s effectiveness without considering how well (or how poorly) the fielders behind him are at the time. It is a statistic that ignores balls batted into play (except balls hit beyond the outfield fence), per its definition by Major League Baseball.

The ERA ignores balls put in play inside the field, and runs scored due to errors by fielders. However, it does not consider at all the quality of the defense players beside him. The ERA also does not care if a pitcher plays for a team that often takes big leads ~ so the pitcher might sacrifice runs for outs to hurry the game’s end.

The FIP sets a league average for defensive capability, and uses that in an equation that includes homers, walks, hit by pitch, and strikeouts. Or, only things the pitcher has control over.

How? The intent is to get an estimate of how well a pitcher prevents earned runs, if the defenders behind him turned batted balls into outs at the league’s average rate. This gets to a beginning number called the Constant, which we will get into below.

How to Calculate FIP in Baseball

Equations to calculate FIP will always include a variable to represent the league-average defense, known as the Constant (@). Those who do not want to calculate their own league defensive averages typically just plug in a Constant around 3.10.

Choose a Constant, and then use this formula to calculate a FIP:

ERA – (13 x HRs given up) + (BB + HBP surrendered, then x3) – (2 x number of total Ks) / Innings Pitched + Constant

Some diehard baseball statistics folks may choose to calculate their own Constant, to get to the most realistic figure as possible using the league-wide ERA, and the league-average defenses.

The easiest way to calculate a FIP nowadays is to just use an online calculator tool. Or, use a search engine to get a pitcher’s current or past FIP.

How to Judge FIP: What is a Good FIP?

An average FIP is quite similar to an average ERA, or somewhere between 2.00 and 3.00. Exceptional FIPs (and ERAs) are below 2.00.

Just like with the ERA, lower FIP numbers indicate more effectiveness, while high FIPs mean pitchers aren’t performing well.

The average FIP for Major League Baseball pitchers in a season is about 3.10, maybe up to 3.20. The lowest FIP for a season post-1920 (the Live Ball era) was 1.39 by Pedro Martinez of the Boston Red Sox in 1999.

Baseball managers and executives can use the FIP in a number of ways. A main one is to examine when a pitcher’s ERA and FIP vary greatly ~ especially if the FIP is a lot lower than the ERA. This could hint at the luck (or bad luck) of a pitcher’s circumstances.

The bottom line is, sometimes pitchers throw very well, but are let down greatly by teammates who can’t field well.

How Baseball Managers Use the FIP Statistic


Finding a pitcher with a low FIP but much-higher ERA, a general manager can dig deeper and find out why. Some reasons they find:

  • Very poor-fielding team behind the pitcher
  • Defenders with very poor range on the pitcher’s team, allowing more batted balls to fall safely for hits
  • Small stadium dimensions, meaning more home runs, and foul balls into the stands that might be caught for outs otherwise
  • High altitude, making balls carry farther, and harder for pitchers to curve or normally move
  • Lively ball which could result in more hits therefore runs and a high ERA (but not necessarily the home runs which would bloat the FIP)
  • Pitching for a high-scoring team, which means the pitcher may have relaxed more because of more leads of 5 runs or more, which can bloat an ERA only because the hurler places strikes and ending the game sooner than a run or 2 (or more)

Managers who find a low FIP and 1 or more of the challenges listed above can gain confidence that the pitcher had bad luck, and may be much better in another environment (e.g. new team with better defenders, and/or a new home stadium).

The Future of FIP the Pitching Statistic in Baseball

For more than a century, the Earned Run Average was the go-to stat to gauge a pitcher’s effectiveness over any period of time. As with many solidly established baseball statistics, including batting average, the ERA was invented by Henry Chadwick, a sportswriter and baseball statistician and historian.

It took a while for ERA to catch on, primarily because most MLB pitchers were expected to complete each 9-inning game, so the Wins-Losses stat ruled supreme at the end of the 1800s.

That changed at the turn of the century when some pitchers became relief specialists, that is, they were inserted into games to take over for whatever pitcher preceded them. (They are designed to provide the previous pitcher with some “relief.”)

The problem was (and is) that relief pitchers do not get assigned a Win in the games they pitch ~ even though they may have contributed greatly to any success.

So the ERA became favored, since it considers a pitcher’s effectiveness over a 9-inning period. The National League began tallying ERA for pitchers in 1912, so it’s been a significant part of Major League Baseball for over a century.

The ERA formula:

Earned Runs allowed / innings pitched x 9

The lower the number, the better the pitching (just like with FIP).

While the FIP is considered a more detailed, deeper look into pitching performances, it still has its detractors. Namely baseball fans or officials who think all kinds of factors impacting the pitcher, like the ballpark pitched in, and even quality of each batter, should be considered.

The FIP is one of several stats considered DIPS, or defense-independent pitching. Others include TIPS, BERA, xFIP and SIERA, among others. (Anyone is free to take raw baseball statistics and formulate how they wish to compare them).

Mostly, baseball researchers are keen to find a way to truly measure the situation, or context, of each event during a pitcher’s stint on the mound. They believe pitchers’ performances can be influenced by the size of the ballpark’s field, which catcher he throws to, even familiarity with individual batters.

Some baseball experts consider the FIP more of a predictor of how a pitcher will regress down the road. For instance, say a pitcher has a 4.60 ERA but a 2.60 FIP. This pitcher has been damaged by defensive errors or plays that should have been made. Probably add in some bad timing, e.g. giving up hits only when runners are on base, and unlucky bounces, and you’re probably close to the reason for the difference.

Note that a lot of today’s pitching statistics tend to try to determine not just errors made by defenders, but plays that should have been made had the individual defender had at least average skills. These get deep into what is average for a defender at a position, which can tend to be a subjective stat.

You might see other pitching acronyms today and in the future that calculate pitching statistics, including the application of a factor for each park on a hitter-friendly or pitcher-friendly basis. Baseball statistics are ever-evolving, especially since the 1980s.

Some Final Words on Fielding Independent Pitching

Some Final Words on Fielding Independent Pitching

In baseball, the statistic Fielding Independent Pitching (FIP) is meant to do just that: judge pitching effectiveness without considering the fielding of batted balls. A good FIP is considered around 3.00 or lower, the same as a solid Earned Run Average (ERA).

In the end, the FIP is a statistic that can be tapped to see if the ERA is “honest.” That is, was a pitcher’s ERA high a season where he pitched for a bad-fielding squad. Or maybe he pitched for teams that scored a lot of runs and was unconcerned about letting in a run or 2 extra per game.

A low FIP number can be valuable toward identifying pitchers that other teams might be scared away from due to a high ERA. The ERA can be bloated for a number of reasons, including a team with several players with really bad range, or a small ballpark allowing too many home runs.

The FIP judges only things a pitcher can control: home runs, walks, and hit batsmen allowed, and strikeouts recorded. It does not judge by whether or not a hitter reached by hit or error, or some of the other very old elements of judging pitching performance.

Related Questions

Question: Why was the FIP invented in baseball?

Answer: Fielding Independent Pitching came around along with a slew of other newfangled statistics starting in the 1980s, when keen baseball watchers determined that the age-old stats used to measure players (like batting average and ERA) were inadequate. Stats that judged a batter’s ability to get on base, or get on base and hit for power (OBP), were added, along with pitcher’s measurement tools like FIP.

Q.: Do we need so many pitching statistics?

A.: It’s like scientists trying to cure cancer: as long as there is a problem, people will try to solve it. In the case of ERA, FIP, and the other pitching stats, it’s all a matter of how good a pitcher is at run-prevention. Since baseball games are won according to who scores the most runs, the best pitchers are considered those who prevent the scoring of runs. To date, there is no perfect stat to determine this; though some swear by the FIP.

See Also:
What Is BABIP In Baseball?
What Do College Baseball Scouts Look for in a Pitcher?
Why Do Baseball Pitchers Lift Their Leg?
What is the Average Velocity of a Division 1 Pitcher?