Hitter xwOBA Underperformers — May 3, 2021, A Review by Mike Podhorzer December 6, 2021 Today, I continue my in-season metric lists with a review of the xwOBA underperformers through May 1. We know that xwOBA isn’t a perfect metric of what a hitter “deserved”, nor is it meant to be predictive. However, it’s certainly better to use it than wOBA itself when trying to forecast rest of season performance. This is especially true when only a small sample of games are in the books, so expected metrics play a more valuable role. So let’s find out how this group of hitters performed over the rest of the season. xwOBA Underperformers Name ISO – Through May 1 BABIP – Through May 1 wOBA – Through May 1 xwOBA – Through May 1 wOBA – RoS wOBA Diff Dominic Smith 0.111 0.275 0.248 0.385 0.296 0.048 Kyle Tucker 0.184 0.158 0.253 0.367 0.415 0.162 Cesar Hernandez 0.066 0.211 0.248 0.352 0.313 0.065 Albert Pujols 0.200 0.164 0.278 0.379 0.313 0.035 Avisail Garcia 0.128 0.263 0.284 0.374 0.361 0.077 Bryce Harper 0.295 0.358 0.448 0.535 0.428 -0.020 Jorge Polanco 0.077 0.237 0.248 0.334 0.368 0.120 Rafael Devers 0.292 0.318 0.403 0.487 0.368 -0.035 Willy Adames 0.128 0.236 0.225 0.304 0.374 0.149 Freddie Freeman 0.245 0.200 0.353 0.431 0.385 0.032 Francisco Lindor 0.052 0.197 0.247 0.325 0.333 0.086 Out of the 11 hitters on this list, nine of them improved their wOBA marks over the rest of the season. The two that failed to do so were already sitting pretty with wOBA marks above .400, so expecting them to enjoy even better results over the rest of the season, regardless of their xwOBA, would have been unrealistic. Four hitters actually posted a rest of season wOBA mark above their early season xwOBA marks. All the wOBA improvements were driven by a combination of both increased ISO and BABIP marks. After his 2019 and 2020 performances, albeit over small samples, Dominic Smith looked like an obvious buy low candidate through the first month of the season. Unfortunately, if you bought low, you still ended up with a poor performer, though less poor than he had been that first month. Through May 1, Smith mostly suffered through a power outage, but his ISO barely increased over the rest of the season. His ISO finished at an embarrassingly low .119, driven by a sub-10% HR/FB rate, both of which were career worsts and well below even the most pessimistic of projections. The Mets recent spending spree guarantees he’s out of a job, and only the adoption of the DH will give him a potential chance at significant playing time. Kyle Tucker was one of the few who went bonkers after the first month, even outperforming his impressive wOBA over the rest of the season. He was a very clear buy low candidate, or at least attempt at a discounted purchase given his absurdly low BABIP. Over the rest of the season, both his ISO and BABIP surged and he finished right where his owners hoped he would when they drafted him. The improved strikeout rate is exciting, so we’ll have to see if that sticks. After a poor first month Cesar Hernandez transformed himself into a complete different hitter. Suddenly, he was a power hitter with a below average BABIP, as he set career bests in both ISO and HR/FB rate, while posting a BABIP below .313 for the first time, as that mark slid all the way down to just .266. The steals are gone, so he’ll need to keep hitting for power to deliver any fantasy value as he joins his new team. Albert Pujols has underperformed his xwOBA every season of the Statcast era, and he highlights one of the missing ingredients of the metric. He pulls grounders into the shift at a significantly higher rate than the average right-hander, which kills his BABIP, but isn’t accounted for in the xwOBA equation. Still, he did improve over the rest of the season, thanks to a BABIP rebound from well below .200, but still fell short of his full season xwOBA. Just once in seven seasons of the Statcast era has Avisail Garcia met or exceeded his xwOBA, though I’d have to dive into some deeper metrics to try to explain why. Still, he came pretty close to matching his first month xwOBA over the rest of the season, as his ISO nearly doubled, and his BABIP increased. Given the difference in home park, I’m not particularly enthused about him as a member of the Marlins. LOL at Bryce Harper’s .535 xwOBA through May 1! He still managed to post an elite .448 wOBA over that first month, so no one in their right mind would expect better over the rest of the season. It’s a testament to his year that he didn’t regress all that much, posting a still-elite .428 wOBA the rest of the way. What’s amazing is that his ISO increased and BABIP remained stable, so I am guessing some combination of a slightly lower walk rate and higher strikeout rate is what caused his actual wOBA to decline. Jorge Polanco made for one of the best buy lows on the list as one of just three who increased their wOBA marks by over .100 points over the rest of the season. He more than tripled his first month ISO over the rest of the season as his HR/FB rate jumped into double digits for the first time and he knocked a career high 33 homers. He’s just 28, so we can’t automatically call this a fluke. Like Harper, Rafael Devers was already enjoying a fantastic season, so you couldn’t expect him to be even better the rest of the way. Most of his wOBA slide was driven by a drop in ISO, but he still managed a career best mark for the season and posted his first HR/FB rate above 20%. Willy Adames was likely dropped in many leagues after his weak first month, but he nearly doubled his ISO over the rest of the season and his BABIP went through the roof. He ended up finishing with an ISO barely below his career best last year, while his BABIP ended up in a normal range. The good news is his 2020 short season strikeout rate spike proved to be a small sample fluke. A full season in a much more hitter friendly park in Milwaukee should help him maintain this level of performance, but his power will be dependent on where his FB% goes, as that spiked to just over 40% after being stable around 31% in his first three seasons. Freddie Freeman with a .200 BABIP?! That could never last. His BABIP rebounded back to normal elite levels over the rest of the season, but it was somewhat offset by a drop in ISO to just under .200. Some of that was due to a decline in FB%. At age 32 now, his projection is up in the air until he signs. Not only was Francisco Lindor a massive disappointment over the first month at the plate, but he also failed to swipe a single base. He did end up as one of the few on this list that posted a rest of season wOBA higher than his first month xwOBA, which is nice, but his counting stats and batting average still fell far short of expectations, ensuring he remained a bust all year, even if he was less busty over the remainder of the season than he was during that first month. The Mets have a new lineup that could be pretty strong, but you have to then wonder if it means Lindor’s steals won’t rebound. That actually might be the biggest question mark.