Statcast Pitcher Studs and Duds - Advanced Metrics Leaders for WAR (Week 13)

Welcome back to another edition of RotoBaller’s Statcast Pitcher Studs and Duds article series! Each week, I will 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. Last week, I looked at a general metric for expected performance. This week, I'll examine an all-encompassing metric for realized performance: wins above replacement (WAR).

WAR was developed as an attempt to measure a player's relative value compared to a replacement-level player, or a readily-available player (think free agent). The calculation is rather complicated and is broken down with further explanation here for those who are interested. The gist of the metric is that the higher a player's WAR is, the more valuable a player they are.

Fantasy managers will have some difficult decisions to make regarding roster moves as they wrap up the first half of their seasons and forecast the second half. Identifying buy-low and sell-high trade candidates can sometimes be easier with broader, more-encompassing metrics. As such, WAR seems like a perfect metric to look at for Week 13!

• Fantasy baseball trade analyzer
• BvP matchups data (Batter vs. Pitcher)
• PvB matchups data (Pitcher vs. Batter)
• Who should I start? Fantasy baseball comparisons
• Daily MLB starting lineups
• Fantasy baseball closer depth charts
• Fantasy Baseball live scoreboard
• Fantasy baseball injury reports

WAR Studs for Fantasy Baseball

All stats are current as of Sunday morning, June 18, 2023.

Zack Wheeler, Philadelphia Phillies

5-4, 3.73 ERA, 1.10 WHIP, 27.4% Strikeout Rate, 3.0 WAR

Upon initial glance, Zack Wheeler's record and ERA would suggest a disappointing season. However, his 3.0 WAR is the second-highest among qualified starters. Fantasy managers may be wondering what Wheeler's fantasy value could be for them in the second half. Should they trust his WAR?

Wheeler has had a few dud starts sprinkled throughout the season, but his underlying stats look like those of a top-tier fantasy starter. He has done a great job limiting hard contact, yet his .305 BABIP is up from the past couple of seasons, suggesting he has gotten unlucky. Further, he has maintained his strikeout stuff thanks to a strong five-pitch mix.

Wheeler's Statcast profile does not suggest a 3.73 ERA and his 3.13 xERA, 3.56 xFIP, and 3.43 SIERA all suggest that he has pitched better than his current ERA. Fantasy managers should have faith that his performance will move toward what his numbers suggest for the second half of the season. I would try to buy low on him if some fantasy managers are worried/disappointed in him.

Sonny Gray, Minnesota Twins

4-1, 2.37 ERA, 1.28 WHIP, 24.8% Strikeout Rate, 2.5 WAR

Sonny Gray has had a useful fantasy career and this season has been top-notch so far. The 33-year-old has compiled a 2.37 ERA, 1.28 WHIP, and 24.8% strikeout rate through 14 starts and has a 2.5 WAR to show for it. Could Gray continue to be a league-winner in the second half?

Gray's performance has been somewhat the opposite of Wheeler's. He hasn't pitched poorly by any means, but he has allowed above-average hard contact. While his expected Statcast metrics are above average, his ERA estimators of 3.70 xERA, 3.69 xFIP, and 4.08 SIERA are markedly higher than his current ERA.

Gray presents an interesting sell-high case in that he should continue to be a fantasy contributor throughout the season, but perhaps not one of the top starters as his WAR suggests. I would be fine with having Gray in my fantasy rotation for the second half, but would also happily trade him if I could get a solid return.

WAR Duds for Fantasy Baseball

All stats are current as of Sunday morning, June 18, 2023.

Martin Perez, Texas Rangers

6-3, 4.54 ERA, 1.50 WHIP, 15.9% Strikeout Rate, 0.3 WAR

Martin Perez had a career season in 2022, leading to some hope that he could be a useful fantasy pitcher in 2023. That has not been the case, as the 32-year-old has posted a 4.54 ERA, 1.50 WHIP, and 15.9% strikeout rate through 14 starts. His 0.3 WAR seems to confirm his performance. Are there any signs that Perez could return to his 2022 form?

The bottom line is that Perez has spent most of his career outside the realm of consistent fantasy relevance. His career ERA sits at 4.44 to go with a 1.45 WHIP and 16.1% strikeout rate. His 2022 WAR was 3.8, but he has never had a WAR above 1.9 outside of that season. He will pitch relatively deep into games but offers little in terms of counting stats.

Some players are better "real-life" players than they are fantasy assets, and Perez is one of them. He brings a veteran presence to teams' rotations and will eat innings, but he tends to allow a lot of hits and walks, which leads to runs. At best, Perez could serve as a streamer in points leagues at this time.

Freddy Peralta, Milwaukee Brewers

5-6, 4.73 ERA, 1.36 WHIP, 24.4% Strikeout Rate, 0.5 WAR

Injuries have kept Freddy Peralta from pitching a full workload during his career, but he has offered fantasy value when he has been on the mound. This season has been different, as his 4.73 ERA and 1.36 WHIP are much higher than his career 3.95 and 1.16 marks, respectively. With such a poor start and a 0.5 WAR, should fantasy managers have any hope he can turn things around?

There are a few positive signs under the hood. First, Peralta has done a good job limiting hard contact. His average exit velocity and hard-hit rate are in the 74th and 59th percentiles of baseball, respectively. He has also posted a career-low 38.7% fly ball rate. Despite all of this, he has a career-high 16.9% HR/FB rate and a 1.66 HR/9 rate. This discrepancy suggests bad luck for Peralta.

Second, Peralta's stuff has been good despite the relative lack of strikeouts. He has seen velocity increases on all of his pitches and has an overall 12.5% swinging strike rate in line with his career 13% mark. He has seen a bit of a dip in called strike rate but has thrown the ball in the strike zone more overall compared to last season and his career. Peralta's current strikeout rate isn't bad, but the underlying numbers suggest it could be higher.

Peralta's underlying numbers look like that of a pretty good pitcher but his peripherals have not yet aligned. He has given up a lot of homers despite limiting hard contact in the air and has seen a dip in strikeouts despite throwing the ball in the zone with swings and misses. Peralta seems like a prime buy-low candidate for the second half of the fantasy season.

More Sabermetrics and Statcast Analysis