Hitter xwOBA Underperformers — Through Apr 17, 2023

We’re about two and a half weeks into the season, which means impatient fantasy owners are going to start cutting or selling low on their slow starting hitters. Before making such rash decisions, it pays to check out the hitter’s Statcast xMetrics. While the metrics have their flaws, it’s the best data we currently have to determine a hitter’s expected performance given their actual batted balls. So let’s review the hitters who have most underperformed their xwOBA marks. This could be your early trade target list if you don’t own these names, and if you do own them, perhaps it’s a reminder to hold strong.

Former top prospect MJ Melendez debuted last season to pretty meh results. This year, he’s suddenly striking out a ton, but his power metrics have blossomed, despite the results not manifesting. Check out that xSLG! All his contact quality metrics look superb — his Hard%, HardHit%, EV, maxEV, and Barrel%. Yet, the results just haven’t come. That should change any day now, though his strikeout rate is still worth watching. He’s catcher eligible, and most of us likely have room to upgrade, so he’s a prime trade target. His value skyrockets in OBP leagues as well.

Josh Naylor already sits against lefties, so an extended slow start could threaten to reduce his PAs against right-handers. That’s the risk right now. However, all his metrics look pretty good, including a career best walk rate, a strong strikeout rate and single digit SwStk%, and a career best Barrel%. But the hits are simply not falling in and his power just hasn’t been on display. Without big upside from either home runs or steals, he should be an easy guy to trade for if he wasn’t already dropped in your league. He’s probably more of a deep mixed or AL-Only league target though given his platoon status, but I think a rebound should be imminent.

Miguel Vargas has operated as the Dodgers’ starting second baseman all season so far after doing a little of everything at Triple-A last year. The good news is he has walked at an absurd 23.2% rate, while striking out less often, and he has yet to hit a pop-up. The bad news is his ISO sits at just .100, he hasn’t homered yet, and his BABIP is well below the league average. So he’s been what we call a zero-category contributor. Amazingly, because of his plate patience, his wOBA sits at a pretty respectable .337, but Statcast really loves him, calculating an expected mark a full 100 points higher. I think the perception of Vargas as a fantasy contributor was a bit overrated to begin with. He doesn’t possess any standout skill that would drive his fantasy stats and he fits more of the mold of an all-around contributor who’s typically undervalued in fantasy circles. While undervalued is a good thing and 10/10 hitters certainly have value, I wouldn’t tend to target those types as a rookie, as it only takes some slight disappointment to turn that 10+/10+ potential into a worthless 5/5. I’ll buy here in a deeper OBP league, but I’m not interested in anything shallower.

It goes to show how slow your start is when xwOBA calculates a .092 mark higher, and yet it still falls below .300. That’s what Jean Segura has endured to begin the year with his new team in Miami. You thought you knew what you would be getting here, that 10+/10+ potential I just discussed for Vargas above. But at age 33, those modest skills only need to decline a bit for that fantasy potential to fall off a cliff. I picked him up for the week as an injury stopgap in my shallow mixed league, but he’s nothing more than that at this point. I would probably hold him in deeper leagues, at least until someone more exciting comes along.

It’s been an interesting start for Ryan Mountcastle, as he’s shown massive power with a .319 ISO and 24% HR/FB rate, but stopped walking, is striking out more, has become an extreme fly ball hitter, and his balls in play have stopped falling for hits. Look at that xSLG! It’s hard to believe he deserves even better power results than he’s posted so far. I think the BABIP will obviously improve from its lowly .200 mark, but his SLG isn’t going to exceed .600, so I don’t think his actual wOBA is going to increase all that dramatically from here. I think he still finishes with a wOBA closer to his current one than his xwOBA, so he’s clearly not a buy low like the rest of these names. Owners should just enjoy the ride.

Gosh Yandy Díaz, if you were planning to suddenly become an extreme fly ball hitter, could you have let me know beforehand so I could have rostered you cheap?! Díaz always had big maxEV numbers, but because he hit so many ground balls, it was wasted. Now he’s suddenly getting the ball in the air, and he’s already nearly halfway to his 2022 home run total. He’s a really interesting case because this performance all hinges on whether he maintains that FB%. If he does, the power should continue, but that BABIP is going to fall well short of his career average and the projections. If he can’t maintain it, he’s likely to revert back to his prior form, which is useless in anything shallower than AL-Only leagues or formats that count OBP. It’s only been 45 batted balls, so it’s impossible to know whether the FB% will last. In fantasy leagues, his owner might actually think he’s selling high here, which might very well prove correct. Like Mountcastle, I think it’s deceptive finding his name on this list, as there’s little chance he proves a buy low with better performance ahead, as this list implies.

Gosh, Kolten Wong has posted a microscopic .135 BABIP, but his xBA is only .179! Sure, Statcast thinks he has dramatically underperformed, but even a .248 xwOBA confirms that he has hit poorly and deserves weak results. Unfortunately, it took just four games for manager Scott Servais to drop him from second to the bottom of the order, first dropping him to sixth, then seventh, and now he’s hit eighth five games in a row. I often wonder how much we would laugh at Major League managers if they were in our fantasy leagues, as they would be dropping slow starters left and right. It’s going to be very difficult for Wong to get back to the top of the order given the names up there now, so he may not rebound anywhere near to his original projections, let along his RoS totals.

That unbelievable one-third of a season 2020 really ruined peoples’ expectations of Juan Soto’s future. That has proven to be the clear outlier so far, though given his still-young age, it’s not out of the realm that he eventually has another similar season, but over a full year this time. This season, he has oddly stopped hitting line drives, which partially explains his sub-.200 BABIP, but Statcast knows his batted ball distribution and still calculates a significantly better .254 xBA, versus his lowly .164 mark. He has actually posted a career high Barrel%, and yet that hasn’t translated into power results at all, with a HR/FB rate barely above last year’s career low, and the first sub-.200 ISO of his career. You really can never expect to wrangle him away from an impatient owner at a discount, but since he’s coming off his worst performance as a Major League and worst fantasy performance last year, this slow start might give you the best opportunity there will ever be.