Yesterday, I discussed seven starting pitchers whose SIERA marks improved the most in May versus April. Those improvements were driven by underlying skills surges — some sort of combination of a higher strikeout rate, lower walk rate, and/or more optimal batted ball distribution. Let’s now flip to the pitchers whose skills declined the most, leading to the largest increases in SIERA from April to May.
We know that pitchers’ skill levels could change quickly, so it’s important to pay attention. A pitcher could suddenly gain/lose velocity, alter his pitch mix, adjust his mechanics, etc, and suddenly become a new version of himself. So let’s dive into the starting pitchers who improved their SIERA marks most from April to May, driven by a significant improvement in skill metrics.
With some insane strikeout rates during his short minor league career, all backed by mid-to-upper teen SwStk% marks and even an absurd 21.5% mark at Double-A in 2019, I have been excited about Tarik Skubal ever since he debuted last year. That performance was quite mixed, as he brought his strikeout stuff, punching out 27.6% of opposing batters, but also allowing a crazy 54.2% FB% rate, which is dangerous in our homer-happy times. Since he allowed an inflated 20% HR/FB rate, it resulted in a sky-high 2.53 HR/9 mark. It’s no wonder he sported an ERA near 6.00! Of course, his 4.12 SIERA suggested better days ahead, but all those fly balls are scary, nonetheless.
Yesterday, I used the Statcast Home Runs Leaderboard to identify and discuss the starting pitchers who have allowed more home runs than expected according to Statcast’s calculation. Today, let’s flip to the starting pitchers who have allowed fewer home runs than expected. Are they any sell highs among this group? Let’s find out.
Earlier this month, I reviewed the hitters who had most underperformed and overperformed their Statcast xHRs. But Statcast doesn’t only calculate xHRs for hitters, it does so for pitchers as well. So let’s review the starting pitchers that have allowed at least two more home runs than Statcast has calculated that they should have been expected to allow.
Let’s continue our search for new everyday hitters, which continue to pop up on a seemingly regular basis.
I’m sure I’m not the only fantasy owner ravaged by injuries this year. With multiple injuries seemingly occurring every day, new players are getting opportunities for regular playing time. Of course, poor play by the incumbent may be another reason for new opportunities. Let’s discuss a bunch of these new everyday starters and determine whether they are worthy of your attention.
Yesterday, I used Statcast’s xBA calculation to discuss the hitters whose batting average’s have most underperformed and could be due for a surge over the rest of the season. Today, let’s flip over to the hitters who have most overperformed their xBA marks as calculated by Statcast. This group could suffer a batting average decline over the rest of the season, and perhaps a significant one, without a dramatic change in underlying skills, like strikeout rate.
While we know that ratios like batting average bounce around during the year, it still takes discipline to look past your hitter’s .194 average through a quarter of the season and vow to hold him, waiting patiently for the rebound you hope occurs. Sometimes, that .194 average is deserved, though that still doesn’t necessarily mean we should expect it to remain that low. Other times, a heaping of poor fortune is mostly to blame for the low average as the hitter actually deserves a higher mark. In the latter, you might have more confidence in a rebound. Let’s use Statcast’s xBA and compare it to actual BA to see which hitters have the most potential for a BA surge over the rest of the season, according to its calculation. Since Statcast isn’t recalculating a balls in play number, then this all falls onto BABIP, so I have included that mark in the below table as well. Just keep in mind that Statcast ignores anything shift-related, so on the whole, hitters most prone to grounding into the shift are going to going to underperform their xBA marks.
Yesterday, I listed and discussed eight starting pitchers who have gained the most fastball velocity in May versus April. Let’s now check the flip side — those pitchers who have lost the most velocity in May compared to April. This could be the first warning sign of a reduced level of performance, or worst case scenario, injury.
