MLB Pitcher Studs and Duds - Advanced Metrics Leaders for xFIP (Week 17)

August 1, 2022

Connelly examines fantasy baseball pitcher risers and fallers, whose xFIP could make them adds, drops, or trade targets for Week 17.

Welcome back to fantasy baseball and RotoBaller’s Statcast Pitcher Studs and Duds article series! The second half of the season is now underway, and I will return to my standard format for this article series. Each week, I select one advanced metric, choose two pitchers with strong values and two with poor values, and analyze what those values may mean for future performance.

With just about an entire half of a season left, I am going to take a look at an expected metric this week: expected fielding independent pitching (xFIP). FIP focuses solely on the events a pitcher has the most control over: strikeouts, unintentional walks, hit-by-pitches, and home runs. It does not consider balls hit in play. xFIP calculates a pitcher's FIP, but it uses the projected home-run rate instead of the actual home runs allowed. The home run rate is determined by that season's league average HR/FB rate.

The main difference between FIP and xFIP is that xFIP is based on the notion that pitchers have more control over how many fly balls they allow than how many of those fly balls leave the park. The specific calculation can be found on MLB's website. The trade deadline is right around the corner for MLB, and it may also be coming soon for fantasy leagues. There is still time to identify buy-low and sell-high candidates, but there may not be many more days for fantasy managers to achieve this through trades. With that, let's dive in to identify some xFIP Studs and Duds!

xFIP Studs for Fantasy Baseball

All stats are current as of Sunday morning, July 31, 2022.

Aaron Nola, Philadelphia Phillies
6-8, 3.32 ERA, 0.93 WHIP, 28% Strikeout Rate, 2.97 xFIP

Aaron Nola is having one of his better seasons to this point, compiling a stellar 3.23 ERA, 0.93 WHIP, 28% strikeout rate, and a 2.97 xFIP that is even better than his ERA. Nola is a pitcher whose underlying numbers have often been better than his peripherals, so it is encouraging to see them so close together in 2022. What about his performance has kept his xFIP so low?

There are a few keys to Nola's performance that have led to a strong xFIP. The main one is the limited number of walks he has allowed. Nola has always limited walks with a career rate of 6.6%, but he has halved that this season with a walk rate of 3.3%.

The other one is his avoidance of home runs. Nola's batted-ball profile has been solid this season, with an exit velocity and hard-hit rate in the 65th and 87th percentiles of baseball to go with an 11.9-degree launch angle. Consequently, he has managed an 11.2% HR/FB%, which is below his career average of 13.6%. He has been just around league average in this department, as his 2.97 xFIP is almost exactly the same as his 2.94 FIP.

Nola has pitched well this season and his peripherals have closely aligned with his underlying metrics, despite being backed by one of baseball's more inefficient defenses. His decreased walk rate in combination with a strong strikeout and home run numbers have led to an excellent xFIP. I would not be surprised to see Nola's walk rate creep up a bit towards his career average, but I still expect him to pitch well.

Alex Wood, San Francisco Giants
7-8, 4.11 ERA, 1.21 WHIP, 23.6% Strikeout Rate, 3.24 xFIP

Alex Wood has had an up-and-down season to this point and has posted a mediocre 7-8 record with a 4.11 ERA, 1.21 WHIP, and 23.6% strikeout rate. However, his 3.24 xFIP is a good deal better than his ERA, which begs the question, is Wood a worthwhile buy-low candidate for the second half?

The good news is there isn't much to suggest that Wood can't be a useful fantasy option for the rest of the season. He has never been a huge strikeout pitcher, but everything else about his profile is solid. He has allowed about league-average hard contact and has kept the ball out of the air with a 6.3-degree launch angle, thanks to his reliance on a sinker. As such, Wood has generated an elite 28% FB rate with a 13.6% HR/FB rate.

Wood had been a fantasy asset for most of his career except for a span of 2019-2020 when he experienced injury issues. He seems to have found his mojo since joining the Giants, and signs suggest that he can be even better for the second half of the season. He may not have a strong defense behind him but does have a favorable home park to pitch in. Wood isn't the most exciting fantasy option, but I think his high floor and strong xFIP make him a buy-low candidate.

xFIP Duds for Fantasy Baseball

All stats are current as of Sunday morning, July 31, 2022.

Chris Flexen, Seattle Mariners
7-8, 3.73 ERA, 1.37 WHIP, 15.9% Strikeout Rate, 5.04 xFIP

Despite his low strikeout rates, Chris Flexen has been a useful back-of-the-rotation fantasy starter for the past several seasons. He has managed a respectable 3.73 ERA through 20 starts this season. However, his 5.04 xFIP is one of the highest among qualified starters. Flexen is currently only rostered in 34 percent of leagues, but is that number too high given his xFIP?

The discrepancy between Flexen's ERA and xFIP appears to be due to good luck. As mentioned, Flexen does not have overpowering stuff, so he allows a lot of contact at a rate of 81.4%. That contact is hard (his exit velocity and hard-hit rate are both in the 22nd percentile of baseball) and in the air with a launch angle of 18.2 degrees and a FB rate of 44.9%.

Despite this, his .281 BABIP is lower than his career mark of .303 and his HR/FB rate of 8.8% is below league average. This explains why his FIP of 4.55, while still higher than his ERA, is a good deal lower than his xFIP.

Some pitchers have the ability to consistently outperform themselves, and Flexen has managed to be one of those pitchers for the last two seasons. However, all signs point to good luck, with a poor underlying batted-ball profile. Flexen's high xFIP indicated that he has particularly gotten lucky in the home run department.

I do not trust Flexen and would consider him a sell-high candidate, although I'm not sure that many fantasy managers would be willing to buy into him at this time.

Jose Urquidy, Houston Astros
9-4, 3.86 ERA, 1.21 WHIP, 17.8% Strikeout Rate, 4.53 xFIP

Jose Urquidy's fantasy story is not all that different from Flexen's. He has managed to be a useful fantasy option throughout his career and has compiled respectable numbers this season. That being said, his 4.53 xFIP is not nearly as good as his 3.86 ERA. Unlike Flexen, Urquidy is rostered in 81 percent of leagues. He may pitch on a better team, but is he really that much better of a pitcher than Flexen?

The underlying metrics suggest that the two are more similar than their rostership would suggest. Both have allowed a lot of hard, fly-ball contact. Urquidy has allowed a contact rate of 81.1% this season to go with an exit velocity and hard-hit rate in the bottom 20 percentiles of baseball. Further, he has given up an average launch angle of 18.5 degrees to go with a 46% FB rate.

His four-seam fastball, his primary pitch at 55.3% usage, has been particularly egregious with a launch angle of 24 degrees and an expected slugging percentage of .564.

Urquidy's HR/FB rate has been higher than Flexen's at 10.8%, but the fact that he allows so much hard contact in the air, particularly with his main pitch, makes me think this metric should be higher.

Other than their teams, I don't see a ton of difference between Flexen's and Urquidy's profiles. Urquidy may be in line to earn some more wins, but I fear that his batted-ball profile will eventually catch up to him to reflect his xFIP. As such, I consider Urquidy to be a sell-high candidate, especially as it seems that fantasy managers are more willing to trust him.

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