Once an undrafted free agent pitcher out of Duke, Matt Mervis soared in 2022. Ending on a high note in Iowa, the first baseman could reasonably have hoped to break camp with the Cubs for much of last winter, due to his addition to the 40-man and his overwhelmingly excellent results over three levels of minor-league baseball. While Mervis had to wait a little bit longer than expected due to the arrivals of Eric Hosmer and Trey Mancini, the lefty got his callup on May 5. By June 15, the Cubs had decided to send the struggling Mervis back down to Triple-A Iowa, later citing that they were working on his swing. Upon returning to Iowa, Mervis continued to rake, but did anything actually improve?
First, it's important to look at Mervis before the callup. On the surface, he absolutely crushed the baseball at Triple A. Posting an impressive 136 wRC+, the former Blue Devil hit six home runs, seven doubles, and 26 base hits. More impressively, he walked 18 times, compared to 19 strikeouts. Based on his raw numbers, Mervis was clearly ready for MLB.
With that said, digging into his hit chart and heat map, there were perhaps a few flaws in his game. Below, you'll see a heat map displaying his hot-and-cold zones for batting average and his spray chart for 2023. Take note that Mervis seemingly feasted heavily on pitches down the middle, but did not cover the plate consistently, getting much colder on pitches on the edges. A very pull-heavy spray chart was the result, with Mervis hitting every one of his six early home runs to right field, and only a handful of batted balls ending up going the other way.
Those trends continued during his time in Chicago. Let's check out the same data for his stint in MLB. Keep note, again, of the majority of his batting average coming from balls that are dead-center, with the small addition of a high-outside blip. There are a lot of similarities between two, suggesting that even though each heat map covers roughly a month of action, Mervis was a similar hitter at both levels in terms of plate coverage:
Where things begin to get interesting with Mervis is when we look at his data from June 16 through the end of the season, at Triple A. There was clearly a change in Mervis's heat map, and while there's just more data and a larger sample size, there is clearly more power being displayed throughout the middle of the field, too. Mervis started to hit home runs more consistently to the middle of field and not everything is as weighted to the pull side. He also showed better control of the plate, particularly, on pitches middle-out and middle-in. There's significantly less blue on this heat map--fewer problem areas. This suggests that there was likely a tweak in approach and swing for Mervis over his time in Iowa:
So what does this all mean for Mervis's future? It looks as if there is both good and bad news. The good is that, looking only at his wRC+, it would seem as though the changes were not something that hurt Mervis overall. Prior to his demotion, as previously noted, his wRC+ was 136. After the demotion, the powerful first basemen posted a wRC+ of 131. Giving him better plate coverage and an approach that uses a bit more of the field, on paper, would be a good thing as well.
Despite the similar wRC+ output, there were a handful of red flags that were being hidden just below the surface, though. Despite the heat map making it seem as if he was hitting the ball more, the opposite was true, as Mervis saw his strikeout rate jump nearly 5%. The strikeouts illustrate that with the swing tweak came a new approach as well; a far more swing-happy one. From June through September, Mervis saw his Swing% jump over five percentage points, in lockstep with the strikeout rate.
More worryingly, the increase in swings was coupled with a decrease in contact. Over this span, his contact rate fell from roughly 75% in the first month of the season to around 66%. A 66% contact rate in Triple A is quite the red flag, as only 11 qualified hitters (out of 80) at the Triple-A level posted worse full-season contact rates. At the MLB level, that would place Mervis squarely in the bottom 10 hitters, as well, and we know that MLB pitchers are much better than their Triple-A counterparts. It would be one thing if the contact rate improved as Mervis showed more competency with the changes. Sadly, instead, Mervis's lowest contact rates of the entire season happened in September. Overall, it becomes quite clear why the front office decided to leave Mervis in Iowa.
Where the Cubs and Mervis go from here is murky. A deeper dive into the contact rates and the Swing% suggests that there clearly was a change, but the overall end result does not appear to be a net gain. Instead, the first baseman is beginning to show signs of being that dreaded "Quadruple-A" type of a hitter, capable of hitting the lights out of Triple-A hurlers while failing to succeed at the highest levels. None of this is to suggest him to be a dead prospect, but despite the wRC+, some of the processes by which Mervis got to his numbers seem nontransferable to MLB. Hopefully, a winter in the cages and with hitting instructors can pair what appears to be better plate coverage with improved contact rates to get the best of both worlds.
What's your level of confidence in Mervis for 2024? How ardently should the Cubs be looking for a first baseman who could push him aside, in the short and the long term?
All charts courtesy TruMedia.