What Happened to Jorge Mateo?

(6/5/23) How Jorge Mateo entered a major slump since his scorching-hot start to the season.

Originally published on Medium on June 5, 2023.

On April 27th, I wrote an article titled “The Reinvention of Jorge Mateo: How Changes to his Swing and Approach are Leading to Success”, in which I analyzed how Jorge Mateo was achieving great success in the first month of the season. At the time, Mateo was the most productive hitter (by measure of Weighted Runs Created Plus) for the Baltimore Orioles and appeared to make sustainable improvements in limiting strikeouts and improving his contact quality. Since the piece was written, Mateo has been one of the least productive hitters in all of Major League Baseball, producing a wRC+ of 19 since April 28th. An increased tendency to chase, bad “batted ball luck”, and struggles against down-and-away Changeups have caused Jorge Mateo to fall into a major slump since his scorching-hot start to the season.

Overview:

As mentioned earlier, Jorge Mateo was one of the most productive hitters in all of Major League Baseball during the first month of the season, however his offensive production has declined significantly since the end of April.

As shown by the table above, Mateo was absolutely dominant at the plate through his first 19 games, slashing .351/.400/.649 (187 wRC+) with 8 stolen bases, while displaying some career-high power. While an above-average BABIP indicated that Mateo’s “batted ball luck” was likely to regress over the course of the season, Mateo’s underlying metrics indicated that his power had the potential to be sustainable.

It has been a different story for Mateo since the publication of my article on April 27th, slashing .165/.202/.243 (19 wRC+) with 7 stolen bases in his last 31 games. While Mateo made some impactful adjustments to his swing and approach over the off-season which were integral to his improved plate discipline and batted ball quality early this season, Mateo has regressed in these areas which have led to his mid-season struggles.

Reason #1: More Chases and Whiffs

One reason why Jorge Mateo has struggled over his past 31 games has been due to a regression of plate discipline. As stated in my previous article on April 27th, “it appears that Mateo made an effort over the offseason to improve his offensive approach by focusing on making more efficient swing decisions (swinging less, and making more overall contact.” In the first month of the season, Mateo did swing less, make more contact in the zone, and chase pitches less often than he did during the 2022 season. However, these trends have reversed in Mateo’s last 31 games.

As shown by the table above, Mateo has experienced a slight increase in his Zone-Swing% and a slight decrease in his Zone-Contact% since the end of April, while also experiencing significant increases in Chase%, Whiff%, and Strikeout%. Swinging at pitches more often, coupled with an increase in Whiffs, is generally not a recipe for success at the Major League level and is a major reason for Mateo’s decrease in offensive production.

As shown by the heat maps above, Mateo has started to swing more at pitches low and away, and pitchers have adjusted accordingly, throwing more pitches in these areas of the strike zone since April 27th. It also appears that an increase in the amount of Changeups Mateo has seen, as well as an inability to adjust to them, has also been a contributing factor to Mateo’s declining offensive production.

As shown by the table above, pitchers have been attacking Mateo with Changeups more frequently as the season goes on. Since Mateo has been swinging more often in general (presumably due to an increased willingness to swing), it only makes sense that pitchers will attack Mateo with a pitch that will throw his timing off and cause him to “pull off” when he is trying to tap into his power.

It appears that pitchers have identified Mateo’s weakness against this pitch in the outer-third of the strike zone, as he is frequently seeing Changeups in this area of the zone and struggles to make contact against the pitch while frequently swinging at it. These struggles against the Changeup, coupled with his increased tendency to chase pitches down-and-away have been a primary reason why Jorge Mateo has seen a decrease in offensive production since the end of April.

Reason #2: Decrease in Batted Ball Quality + Bad “Batted Ball Luck”

Another reason why Jorge Mateo has seen a sharp decrease in offensive production has been due to a decrease in batted ball quality, as well as some bad “batted ball luck”. A major reason why Mateo was able to experience such a power surge early in the season was due to his increased Hard Hit and Barrel Rate. However, over a larger sample size through the first two months of the season, these metrics have regressed closer to the mean that Mateo has exhibited over his first three seasons. Hard Hit and Barrel Rate are good indicators of a player’s power ability, and it is no coincidence that Mateo’s power numbers have declined at a similar rate as the decline in his batted ball metrics.

In a recent article in The Baltimore Banner, Mateo explained that he believes he is experiencing some bad “batted ball luck” as many of his hard-hits are turning into outs since they’ve been hit directly to opposing fielders. “I think things are still going pretty well, and if people are paying attention, a lot of the balls I hit are just right at guys,” Mateo said. “Unfortunately, that’s the way things go sometimes. They’re on the field. Just a lot of hard-hit balls going right at guys.”

As shown by the table above, Mateo’s observations are backed up by his BABIP and xwOBA, as both of these metrics indicate that he has been experiencing less than expected results on batted balls in play. Conversely, some of Mateo’s early-season success can be attributed to the high BABIP and xwOBA he produced during the first month of the season. While his BABIP can be expected to experience some positive regression moving forward, a decreased ability to hit the ball hard consistently has resulted in some bad “batted ball luck”, causing a decline in Mateo’s offensive production.

Potential Solutions + Concluding Thoughts

Despite these struggles, there are a couple adjustments that Mateo can make to his offensive approach in order to regain some of the offensive production he experienced early in the season. According to the aforementioned Baltimore Banner article, “Mateo’s hands [have] crept back into bad habits. He added an extra movement at times, drawing his hands back in a deeper load before swinging, and the tiniest adjustment threw off his timing.” I’ve attached a video of his Mateo’s swing from before and after April 27th below, and I personally can not identify this slight altercation in Mateo’s swing. Still, I will take the article at its word and the first suggestion I would make to Mateo would be to limit his movements in his load, as this adjustment was vital to his early-season success.

Video from 4/25: 8ceab29b-ee35–4670-aa55-d716f23dde34.mp4

Video from 5/31: 5d8a4fad-7f4d-4d12-a90b-ea1720af6f80.mp4

My second adjustment would be to focus on being able to make contact on Changeups on the outer-half of the strike zone. In my opinion, the best way to accomplish this objective would be to stop “selling out” for power. Throughout the entirety of this season, Mateo has been pulling the ball more frequently than he has at any point in his career, and I believe this is the result of trying to make contact with the ball “out in front” in order to pull the ball with power. If this indeed has been Mateo’s mindset, then it makes sense why he has been experiencing a weakness on down-and-away Changeups. Once his swing mechanics are refined, it might make more sense for Mateo to focus on utilizing his hard hit and sprint speed abilities to produce high BABIPs, as opposed to selling out for power which he may not be able to consistently tap into. With these adjustments, Jorge Mateo might be able to regain some of the improved offensive abilities he displayed early in the season, and further prove that he can be the starting shortstop for the Baltimore Orioles for the foreseeable future.

Follow @MLBDailyStats_ on X (Twitter) for more in-depth MLB analysis. Statistics provided by Baseball Savant and FanGraphs. Data as of June 2nd, 2023.