This article is part of our DFS Baseball 101 series.
In a recent installment, we attempted to alter some long-standing paradigms about assessing a hitter's performance. We did so by explaining how Weighted On-Base Average (wOBA) is a more accurate and nuanced indicator of offensive production than conventional batting average, a figure that most of us were conditioned to associate with offensive success or failure.
Pitching performance happens to have a counterpart to batting average that has likewise been ingrained in us as an all-encompassing indicator of prowess on the mound, or lack thereof: Earned Run Average (ERA). However, much like how conventional batting average had the inherent deficiency of treating all hitting "events" the same, ERA has its own fundamental flaw in terms of a lack of depth.
The Inherent Deficiencies of ERA
While it certainly provides us with data pertaining to how many runs are scored by the opposition when a pitcher is on the mound, it doesn't offer sufficient insight into what type of hits went into those runs crossing the plate and, just as important, how many other factors outside of a pitcher's control conspired to allow some batted balls to fall in safely when they could have been prevented. Additionally, ERA isn't equipped to inform us how outs are being recorded, or how often a pitcher is part of his own undoing by issuing walks or hitting batters. This type of information can be of particular value when selecting pitchers for daily fantasy baseball lineups.
We've previously touched on some events that transpire on the diamond that fall outside a pitcher's control: team defense, BABIP (Batting Average of Balls in Play) and just plain old luck. Some of these can often skew the number of runs a pitcher is charged with, often within one outing, and while ERA does issue pitchers a mulligan for those runs that originate from an official error by a teammate, it is not designed to account for runs that could have been prevented with, say, an infielder with better range.
Ins and Outs of FIP
As has been the case with the advent of many other advanced metrics, a need to drill deeper and obtain a more accurate measure of a player's true performance eventually led to the creation of a new statistic: Fielding Independent Pitching (FIP). As usual, the baseball analytics site Fangraphs provides a thorough background of the origins of FIP in their sabermetrics library, which you can read here.
FIP isolates the results of the four events pertaining to pitching that do not include defense: strikeouts, walks, hit by pitches and home runs allowed. The one common thread among the four? They're all of the events that a pitcher can directly control while on the mound.
By essentially eliminating all of the other possible factors outside of a pitcher's control , FIP provides us with an effective method of evaluating pitchers for our daily fantasy baseball lineup.
As with all other metrics, there is a specific formula for calculating FIP:
FIP = ((13*HR)+(3*(BB+HBP))-(2*K))/IP + constant
Naturally, there's no need for you to have to calculate FIP on your own, as current data for any pitcher is available through each pitcher's profile on RotoWire under the "advanced stats" section. However, I've included the formula to illustrate the fact that like the previously discussed wOBA, FIP assigns different weights to the different possible outcomes that go into generating it.
As you'll see, home runs are rightfully given the greatest weight (13), while walks and hit batsmen are a distant second (3). Strikeouts are provided the lowest weight of the four possible outcomes (2). As with wOBA, the weights assigned are intended to properly reflect the real-world impact that the events have within the field of play with respect to run prevention.
The "constant" referred to in the formula is designed to bring FIP in line with league average ERA. In that manner, a pitcher's ERA and FIP normally have a close-knit relationship in which they fall very closely in line with each other, particularly over larger sample sizes. However, it's in the cases where there's a gap between them that we can potentially spot trends that can help us in setting our daily fantasy baseball lineups.
Why FIP over ERA in Daily Fantasy Baseball?
So how exactly do we deploy FIP to make decisions on pitchers in daily fantasy baseball? Simply stated, examining a pitcher's FIP is often a better indicator of a pitcher's true ability—and therefore, his potential future improvement or regression—than ERA because it measures the aforementioned four events that are within the pitcher's control. If we rely solely on a pitcher's ERA, we could certainly run into instances where we immediately disqualified a pitcher from consideration, only to see that same player turn in an unexpected gem that could have led to a handsome return.
Conversely—and there's usually a "conversely" when looking at the use of any metric—we can also be easily taken in by a pitcher whose ERA is the veritable wolf in sheep's clothing. In other words, it's entirely possible, particularly over smaller, in-season sample sizes, to see a pitcher's ERA outperform his FIP due to it some stalwart defense behind him, some timely stranding of runners, or a stretch of low BABIP against him.
A pitcher's batted ball profile can also play a part in FIP. For example, pitchers who tend to elicit an above average rate of fly balls have a better chance at having their ERA check in lower than their FIP, as fly balls result in outs much more often ground balls or line drives. Likewise, ground-ball pitchers can see their ERA bely their efficacy on the mound, as those types of hits are more likely get through the infield safely, particularly when the aforementioned factor of questionable defense is at play as well.
It's usually helpful to crystallize the concepts behind the metric with some actual, in-season examples, so we'll close out this installment with some that illustrate what we've been discussing.
The Rangers' Colby Lewis serves as a revealing case of how a superior strand rate, low ground ball rate and high HR/FB rate can lead to a sizable gap between ERA and FIP. Lewis' ERA and FIP were almost two full runs apart, so if we were looking solely at his ERA when evaluating him for a daily fantasy baseball lineup, we could easily conclude he's turning in a superior season at age 36.
However, a further look reveals that Lewis was leading the league by stranding 92.3 percent of the runners that reach base against him. Meanwhile, his fly ball rate was 42.8 percent and the batting average of balls in play against him was a mediocre .263 as well, meaning that he was likely been the beneficiary of some good fortune and defense behind him when hitters have made contact. All of these factors certainly played into Lewis being able to generate more outs and limit the damage against him in terms of runs, which in turn produces a solid ERA.
Therefore, we can see by these numbers that while Lewis' ERA was undeniably impressive, an elevated HR/FB rate (1.53) and low strikeout rate (6.71 K/9) were playing into his elevated FIP and could also be a harbinger of the unsustainability of his ERA. Lewis' career ERA is a subpar 4.70, lending even more credence to this theory. If his effectiveness in stranding runners goes down a couple of notches and/or batted balls start finding green more frequently—once again, his career ERA would appear to imply is bound to happen—we could see Lewis' results start to head south rather quickly.
Our opposite example is David Price, who's caught plenty of flak in baseball-crazed Beantown for largely underperforming relative to the enormous contract he received from the Red Sox. However, a look at his admittedly unsightly ERA belies a stellar FIP. As with Lewis, the building blocks for the respective figures are predictable.
Price had stranded runners at a 60.1 percent rate, which ranked as the second-lowest in the majors. His BABIP was also a robust .337, 12th-highest among qualifying starters. Both of these have played an integral role in an ERA that would normally be associated with a much lower quality of pitcher.
However, Price produced a minuscule 0.87 HR/9 rate, while whiffing opposing batters at an impressive rate of 10.97 per nine innings. His 2.17 BB/9 rate was solid enough to keep his FIP down as well. Overall, his superior performance in these categories indicates that he's still way above average in the areas of control, keeping the ball in the park and overpowering hitters. Therefore, it's entirely possible a positive stretch is coming.
While these examples serve the purpose of providing you with some tangible illustrations of how and why ERA and FIP can vary, they are particular to the 2016 season. As a long-term guide, refer to the following parameters for determining the quality of a pitcher's FIP as provided by Fangraphs. Since FIP is tied in with league average ERA, however, the good news is that you can pretty much guide yourself by what you've already come to know as superior, average and below average figures in that category to evaluate a pitcher's FIP.
To be clear, FIP, while a more detailed evaluator of pitching performance than ERA, is still just one metric among many. In daily fantasy baseball we must always use any metric in conjunction with that day's particular matchup. However, as far as making sure we do not make premature evaluations on the candidacy of a starting pitcher, FIP can serve as a highly valuable measure in helping us make our DFS pitching selections.