Let’s Leave The Fielders Out Of This: What is FIP?
In modern-day baseball times, inquiring fans can go down a statistical wormhole, as there seems to be numbers surrounding everything in baseball. It is important to draw the distinction between which stats are direct results of performance, and which stats are the products of in-depth mathematical formulas.
Fielding-Independent Pitching, a commonly-used pitching metric, sort of falls in between. Well-known sabermatrician Voros McCracken developed the fielding-independent model in the early 2000s as a way to measure a pitcher’s effectiveness with no other factors involved other than the pitcher’s performance. FIP was developed in conjunction with McCracken’s Defense Independent Pitching Theory (DIPS Theory). Strikeouts, walks, batters hit by pitches, and homeruns are all factors involved in determining the FIP, as well as innings pitched and a league-wide constant variable. Long story short, FIP produces a number that acts as predictor to what a pitcher’s ERA should be, with no fielding factors involved.
DISTINGUISHING ERA AND FIP
While FIP is certainly not the gold standard for judging pitching trends, it can provide context to a pitcher’s season, if nothing else. According to Fangraphs’ FIP scale, a pitcher’s FIP can be interpreted like this:
Above Average: 3.80
Below Average: 4.40
These numbers are standardized for the 2016 season. FIP is standardized with the aforementioned constant in order to level it off with the league’s average ERA. With the constant in mind, one can easily make a comparison between a pitcher’s FIP and ERA for a season. FIP provides context to whether a pitcher is out-performing or under-performing the likely ERA based upon his pitching profile. For example, if a pitcher has an ERA significantly lower than the FIP, he is benefitting from a number of potential factors, including defense, inducing soft contact, and most likely just some good old-fashioned luck. On the other hand, if a pitcher has a FIP lower than his ERA, he is likely running into some bad luck with batted balls or has a less-than- stellar defense behind him. This creates some interesting scenarios, as some pitchers have had seasons that defied FIP logic. In compiling data for this exercise, I found every ERA-qualified season for active players, and was able to pull both the ERA and FIP for each particular season (with much help Baseball Reference’s Play Index). After pulling this data, I subtracted each pitcher’s ERA from his FIP (FIP-ERA), in order to find which player is either overachieving or underachieving based upon his FIP. If the season were to end today, 2017 would feature the 7 best overachievers in terms of FIP-ERA:
1. Gio Gonzalez, 2017: +2.38 (5.24 FIP, 2.86 ERA)
2. Ervin Santana, 2017: +2.30 (4.10 FIP, 1.80 ERA)
3. Lance Lynn, 2017: +2.17 (4.70 FIP, 2.53 ERA)
4. R.A. Dickey, 2017: +2.03 (6.20 FIP, 4.17 ERA)
5. Derek Holland, 2017: +1.88 (4.35 FIP, 2.47 ERA)
6. Jeremy Hellickson, 2017: +1.87 (5.31 FIP, 3.44 ERA)
7. Andrew Cashner, 207: +1.86 (5.04 FIP, 3.18 ERA)
Hellickson is an interesting case, as he has vastly over-performed his FIP in two other seasons. In 2011, Hellickson posted a 2.95 ERA vs. a 4.44 FIP, and in 2012 he posted a 3.10 ERA vs. a 4.60 ERA. While the cases above are beneficial for the individual pitcher, FIP can also work the other way, so here are the perceived underachievers according to FIP:
1. Josh Tomlin, 2017: -2.94 (3.76 FIP, 6.70 ERA)
2. Bartolo Colon, 2017: -1.81 (4.57 FIP, 6.38 ERA)
3. Ricky Nolasco, 2009: -1.71 (3.35 FIP, 5.06 ERA)
4. Jeff Samardzija, 2017: -1.68 (2.89 FIP, 4.57 ERA)
5. Edinson Volquez, 2013: -1.47 (4.24 FIP, 5.71 ERA)
With 2017 being on the top of both of these leaderboards, it’s safe to say a lot of the people towards the top of both of the overachiever and underachiever leaderboards will have their ERA normalized toward their FIP. Likely the most interesting name on either list is Ervin Santana, whose 1.80 ERA and 2 shutouts have Minnesota Twins fans calling for a Cy Young Award. Santana’s FIP sits at 4.10, does this mean he will regress toward his FIP, or can he keep his stellar start going?
ERVIN SANTANA, DESTROYER OF FIP
Coming off of a 2016 season in which he had arguably his best Major League season, Santana established himself as the de facto ace of a less-than-heralded Minnesota Twins pitching staff. Santana came out of the gates firing with 7 strong innings on opening day, and he hasn’t slowed down one bit. Through 10 starts, Santana has won 7 games, thrown 2 shutouts, and posted a paltry 1.80 ERA, which leads the league. While his ERA jumps immediately off the page, Santana’s FIP sits at a pedestrian 4.10. What causes this discrepancy is Santana’s somewhat alarming peripheral stats. For example, if the season ended today, Santana’s .134 batting average against would be well ahead of the best qualified full season, which was Pedro Martinez in 2000 (.167). Another trend statistic, batting average of balls in play (BABIP) can usually tell if a pitcher is getting some good fortune in his pitching. Santana’s mark of .138 BABIP against would also be by far the single-best mark posted in the history of BABIP data being available. For reference’s sake, batters have a career batting average of .250 and a BABIP of .284 against Santana. It remains to be seen if Santana can keep his record setting pace of AVG and BABIP, but it seems unlikely that he will keep his groundbreaking pace. The main factors of FIP have to do with hits, homers, walks, and strikeouts, which are general ways to assess a pitcher’s effectiveness without involving the defense. Let’s look at those vs. Santana’s career marks:
- 2017: 4.0 H/9
- Career: 8.6 H/9
- 2017: 0.9 HR/9
- Career: 1.1 HR/9
- 2017: 3.5 BB/9 (career high)
- Career: 2.8 BB/9
- 2017: 6.4 SO/9 (second-lowest of career)
- Career: 7.2 SO/9
As you can see above, Santana has managed to post a 1.80 ERA despite walking more hitters and striking out less hitters, two factors that would seemingly be negative factors for a pitcher. As mentioned above, he has held hitters to preposterous lows in AVG and BABIP. On top of that, Santana has managed to leave a ridiculous 91.5% of runners on base, which would also be an all-time record. One other factor that has helped Santana is the improvement of the defense behind him, as the Twins have gone from a bottom-barrel defense to one of the league’s best. It remains to be seen if Santana can keep this ridiculous pace going, but it would seem as though he will regress toward his career means. As a Twins fan, I would love to see Santana continue his dominance, but a Santana that is even close to his current status would be more than welcomed.
(statistics courtesy of baseball-reference.com and fangraphs.com)