Greatness in Relief, Obscured

Since 2002 — the first year we have batted ball data — there have been 2,465 instances of a relief pitcher throwing at least 30 innings during one of those 14 years, or an average of about 176 relievers doing so per year. That’s six per team each year, essentially.

Of those 2,465 pitcher seasons, the reliever in question has only managed to post an xFIP- of 60 or better 48 times. Craig Kimbrel has done it the last three years. Billy Wagner did it three times. Jonathan Papelbon and Mariano Rivera did it twice. Aroldis Chapman did it last year. You get the idea.

While it’s not the perfect measure of a relief pitcher, xFIP- focuses on the things that great relievers do really well: rack up strikeouts, limit walks, avoid fly balls. The minus sign indicates that it is park and league adjusted, so it’s not going to be biased by the recent rise in strikeout rate, allowing us to better compare seasons across different years. An xFIP- of 60 means that a pitcher was 40 percent better than the league average based on his BB/K/GB rates, and it’s basically the exclusive home of really great relief seasons.

As a group, those 48 relievers combined to throw just over 3,000 innings, and their weighted average ERA-/FIP-/xFIP- was 49/47/53. Because relievers tend to post lower than average BABIP and HR/FB rates, they also post slightly lower ERAs than xFIPs overall, but as this group shows, the skew isn’t too huge. Now, just for fun, here’s all of those 48 seasons plotted by each pitcher’s respective ERA-, with their xFIP- shown for reference.

From the left to the right, we see 47 relief pitcher seasons with excellent peripherals and an ERA- ranging somewhere between 19 (2009 Mike Adams) and 79 (2010 Rafael Betancourt). Then we see the outlier.

With an xFIP- of 54 and an ERA- of 138, Danny Farquhar is currently having one of the strangest relief seasons in recent history. By strikeout rate, he’s currently #7 in the majors among relief pitchers at 35.7%, coming in just ahead of Kenley Jansen and Trevor Rosenthal. His walk rate isn’t great, but a 10% BB% won’t kill you if you’re racking up the strikeouts. And, unlike some pitchers who get a ton of strikeouts by pitching up in the zone, Farquhar actually gets a league average rate of ground balls, which should help limit the number of home runs he gives up.

And yet, Farquhar has a 5.45 ERA, which rates 144th out of 150 qualified relief pitchers this year. By runs allowed, Farquhar has been well below replacement level, racking up a -0.6 RA9-WAR. By FIP, Farquhar has been well above replacement level, racking up +0.7 FIP-WAR. At this pace, the gap between his FIP and RA9 WARs would be +2.5 wins over a full season, a mark matched only by Chad Qualls (176 ERA-, 93 xFIP-) in 2010.

As is the case with pretty much every instance where there’s a large divergence between FIP and ERA, Farquhar’s had BABIP problems, but even a .378 BABIP doesn’t often result in an ERA three runs higher than a pitcher’s FIP. In fact, the breakdown of the Fielding Dependent Pitching numbers shows that the inflated BABIP has been responsible for less than half of the difference, with the timing of when he’s given up those hits accounting for a larger portion. With the bases empty, opponents have hit .206/.280/.309 against Farquhuar, but they’ve managed a .276/.359/.382 mark with runners on base. Still not great, but good enough to drive home a good portion of the runners who have managed to reach against him in the first place.

Farquhar’s also been used primarily as a mutli-inning reliever, recording 4+ outs in 13 of his 22 appearances. Because he’s been asked to extend himself and save the rest of the Mariners bullpen, he hasn’t had the benefit of another reliever with the platoon advantage coming in and stranding his runners. He’s had to get himself out of jams, and thanks to a .432 BABIP with men on base, he hasn’t done it successfully all that often.

But, of course, these things aren’t particularly predictive, and there’s no reason to think Farquhar has some kind of personality flaw that causes him to fold when runners reach base. The fact that he’s running a 2.17 xFIP tells us far more about his potential effectiveness going forward than the 5.45 ERA. There just aren’t many examples of pitchers who can strike out 35% of opposing batters but still aren’t effective big league relievers.

We’re still definitely dealing with small sample size mania, as Farquhar is a minor league veteran whose success has come almost completely out of nowhere. A year ago, he was the second prospect traded to Seattle for Ichiro Suzuki, and he had been a side-armer throwing in the high-80s for most of his career. Now throwing over the top and hitting 96 regularly, Farquhar has turned himself into a pretty interesting relief pitcher.

Danny Farquhar is due for regression in both directions. He’s almost certainly not the third best reliever in baseball, as his current xFIP would suggest, and he’s almost certainly not a useless scrub, as his current ERA would suggest. His xFIP will go up and his ERA will go down. Given the ridiculous strikeout rate, expect him to settle in closer to the 2.17 than the 5.45.