If you’ve ever wondered how much better a pitcher would be if the defense behind him would quit literally dropping the ball, FIP can clue you in.
There are dozens upon dozens of statistics in baseball that can be used to judge a pitcher’s performance, from basics like wins and strikeouts to the more complex wins above replacement and expected weighted on base average against.
Fielding Independent Pitching — FIP for short — falls somewhere in between those two extremes: A bit arduous to calculate on your own, but not that difficult of a concept to grasp.
By stripping away most of the stuff that’s out of a pitcher’s control, FIP aims to answer the question: How good would this pitcher be with an average defense?
We’ll explain everything you need to know about this pitching acronym, including the formula for it, some of the best to ever do it and how you can utilize it to kick some serious butt in fantasy baseball.
What Is FIP and What Is Its Purpose?
You may have heard of “three true outcomes” hitters, which are those who either homer, whiff or walk in roughly half of their plate appearances.
Well, FIP is kind of the pitching side of that, focusing almost exclusively on those events.
We’ll get into the actual formula momentarily, but the goal of FIP is to take fielding / balls in play out of the equation when gauging how productive a pitcher has been, focusing instead on the things that a pitcher can most control.
By removing hits, errors and runs allowed in general, FIP is meant to tell us what a pitcher’s ERA *should* be if he had perfectly average luck and a perfectly average defense behind him.
Over a large enough sample size, a pitcher’s ERA and FIP do end up being pretty similar. Of the 621 pitchers who have logged at least 1,000 innings pitched since 1969, only two (Len Barker and Glendon Rusch) had an ERA at least 0.65 higher than their FIP, and only three (Dave Dravecky, Ryan Franklin and Jim Palmer) had an ERA at least 0.65 lower than their FIP. That’s less than one percent who maintained a considerable divide over the course of their careers.
As such, comparing a pitcher’s FIP to his ERA in the middle of a season is one of many ways to get a sense of whether said pitcher is due for some regression (in either direction).
How is FIP Calculated?
Most of the oft-referenced statistics in baseball are either simple counting stats (home runs, runs batted in, wins, strikeouts, etc.) or can be calculated by hand without too much consternation (AVG, ERA, WHIP, K/9, etc.).
FIP…not so much.
The formula for FIP is: [(13A + 3B - 2C) / D] + a FIP Constant, where A is home runs allowed, B is the sum of walks allowed and batters hit by pitch, C is strikeouts and D is innings pitched.
And before you can calculate FIP, you need that FIP Constant. That formula is: E - [(13A + 3B - 2C) / D], where E is league-wide ERA for that season (or seasons) and A, B, C, and D are the league-wide versions of the same statistics from the FIP formula.
So, yeah, good luck crunching those numbers via pencil and paper.
The point of the FIP Constant is to put FIP on the same scale as ERA. When the league-wide ERA in 2000 was 4.77, so was the league-wide FIP. Same goes for 2014, when both marks were 3.74. They always end up the same. But the Constant itself changes slightly from one year to the next, ranging from as low as 2.96 to as high as 3.25 over the past three decades.
As a sample calculation, in 2024, league-wide ERA was 4.08, with 43,116.1 IP, 5,453 home runs, 14,929 walks, 2,020 HBPs and 41,197 strikeouts. Plug those numbers into their respective slots above and you get a FIP constant of 3.1675.
Among pitchers who averaged at least one inning pitched per team game in 2024, Chris Sale (177.2 IP, 9 HR, 39 BB, 8 HBP, 225 K) had an MLB-best FIP of 2.09, while Griffin Canning (171.2 IP, 31 HR, 66 BB, 6 HBP, 130 K) brought up the rear with a 5.26 FIP.
For what it’s worth, there is no upper limit on FIP, as it would be infinity for a pitcher who gives up at least one home run, walk or HBP without recording an out. Such was the case for Carl Edwards Jr. in 2024, allowing two walks and retiring no batters in his only appearance of the season.
There is a lower limit to FIP, though. If a pitcher gave up no home runs, walks or HBPs and recorded every out by way of a whiff, his FIP would be negative-6.00 plus whatever that season’s FIP constant is. For instance, in Josh Hader’s debut with the Houston Astros in 2024, he pitched a perfect inning of three strikeouts with no base runners allowed. At that point, he had a FIP of negative-2.83 (negative-6.00 plus the FIP Constant of 3.17).
In MLB history, the best career FIP belongs to Ed Walsh, who had a mark of 2.02 from 1904-17.
In much less ancient history, there are 11 pitchers who have logged at least 1,000 IP since 1969 with a sub-3.00 FIP:
- Jacob deGrom (2.59)*
- Mariano Rivera (2.76)
- Clayton Kershaw (2.83)*
- J.R. Richard (2.86)
- Bob Gibson (2.87)
- Chris Sale (2.89)*
- Pedro Martinez (2.91)
- Lee Smith (2.93)
- Bruce Sutter (2.94)
- Rollie Fingers (2.95)
- Nolan Ryan (2.96)
*Still active at time of publish
On the flip side of that coin, the worst FIP in MLB history among players with at least 1,000 IP belongs to Scott Elarton with a mark of 5.41 from 1998-2008. In 1,065.1 innings of work, he allowed 192 home runs, 418 walks and 40 HBPs while striking out a modest 698 foes.
How FIP Helps in Fantasy Baseball
Memorial Day is traditionally the point in the MLB season when baseball folks agree there’s enough data (roughly one-third of the campaign) to start actually looking at the standings and jumping to conclusions on how both players and teams are performing.
Same goes for looking at FIP for fantasy purposes.
FIP—and more specifically ERA minus FIP—is a fantastic in-season data point for fantasy baseball players to leverage.
As previously noted, FIP gives us an estimate of what a pitcher’s ERA ought to be with a normal amount of luck. So, when it’s a couple of months into the regular season and a pitcher has, say, a 5.00 ERA and a 3.00 FIP, there’s a good chance things are about to turn in his favor.
On Memorial Day 2024, Houston’s Spencer Arrighetti had a brutal 6.93 ERA for the year but a respectable 3.94 FIP. Lo and behold, he had a 3.69 ERA the rest of the way, ranking top 20 in the majors in total strikeouts over that four-month stretch.
It was a similar story the previous year, with Jameson Taillon (8.04 ERA, 4.44 FIP at Memorial Day) becoming a serviceable fantasy asset with a 4.04 ERA after that. David Peterson (8.08 ERA, 4.77 FIP at Memorial Day) was even better than that with a 3.38 ERA over his final 19 appearances of 2023.
It’s perhaps even more noteworthy that this works in the opposite direction, too.
On Memorial Day 2024, there were six pitchers with at least 50 innings pitched and a FIP at least 1.80 greater than their ERA: Triston McKenzie (3.44 ERA, 5.52 FIP), Ronel Blanco (1.99 ERA, 3.99 FIP), Austin Gomber (2.76 ERA, 4.63 FIP), Andrew Abbott (2.68 ERA, 4.55 FIP), Marcus Stroman (2.76 ERA, 4.59 FIP) and Tyler Anderson (2.52 ERA, 4.33 FIP).
Each one had significant “looking great so far, but the sky might be about to fall” ERA minus FIP marks.
And in most cases, that’s exactly what happened.
McKenzie imploded to the tune of an 8.87 ERA over the course of the next month before getting shut down with a UCL sprain. Gomber had a 5.84 ERA the rest of the way. Stroman’s was 5.34. Anderson landed at 4.54. Abbott’s ERA was 4.44. And while Blanco (3.19 ERA) was the exception, his post-Memorial Day FIP of 4.22 still suggested he was lucky not to collapse more than he did.
The trick, of course, is trusting in the data.
Picking up a guy with an ERA up in the 7.00-8.00 range because he has a solid FIP is a serious leap of faith, and one that sometimes doesn’t pay off in the slightest.
It’s even tougher to bring yourself to trade away (or stop paying for, if we’re talking Daily Fantasy Sports) someone with a sub-2.80 ERA who has been one of your go-to pitchers. But it easily could be the move that propels you to a championship.
To be clear, though, Memorial Day isn’t the only time that FIP is helpful for fantasy purposes. It is more useful as an in-season data point than it would be in your pre-draft preparation, but you can use ERA minus FIP to your advantage at any point from early May through Labor Day and beyond.
Frequently Asked Questions
What’s the difference between FIP and xFIP?
The fundamental difference between these two mostly similar statistics is that while FIP is calculated using actual home runs allowed by the pitcher, xFIP uses expected home runs allowed by combining the number of fly balls allowed by the pitcher with the league-wide ratio of home runs per fly ball.
Basically, FIP assumes that a pitcher has at least some control over whether a fly ball becomes a home run, while xFIP does not, expecting pitchers to eventually regress toward the league average HR/FB ratio.
For what it’s worth, among the 202 pitchers who logged at least 1,000 innings pitched from 2004-2024, all but one had a FIP that landed within 0.40 runs of his xFIP, with Brett Myers (4.38 FIP, 3.79 xFIP) the lone exception.
What is a good FIP in baseball?
To some extent, it depends on whether we’re talking about a starter or a reliever, the sample size and the season in question.
Much like ERA, a year-end FIP below 3.00 is mighty impressive for a starting pitcher in today’s game, 4.00 is roughly the league average and anything north of 5.00 is dreadful.
For a strikeout-heavy reliever, though, a sub-2.00 FIP is relatively common, and you’ll even see sub-1.00 every once in a while, as was the case for Craig Kimbrel in 2012 (0.78), Aroldis Chapman in 2014 (0.89) and Edwin Diaz in 2022 (0.90).
Is FIP a better statistic than ERA?
Again, context is key here.
Are we handing out year-end awards or are we making plans for free agency?
Because ERA and FIP are set on the same scale, a good ERA is a good FIP and vice versa. But if there’s a significant difference between a pitcher’s marks in these departments, a team would be happy if it already had a pitcher whose ERA was much better than his FIP, but might be just as happy about newly signing a pitcher whose ERA has been much worse than his FIP.
Sleeper: The Best Source for Baseball News
Now that you know a bit more about one of the primary statistics used in forecasting pitching, you might want to start applying that new-found knowledge in the world of fantasy baseball.
If so, give Sleeper a try. The app is top notch, and its fantasy offerings are plentiful, from breaking news, to Sleeper Picks to season-long leagues.
If you’re still relatively new to the world of baseball or just looking to expand your knowledge of the game, we’ve got all sorts of articles to help you out, from baseball rules for beginners, to an explanation of baseball statistics, a primer on the positions in baseball and, of course, tips for playing fantasy baseball. (Links for all when published)