Paul DeJong has been a steady contributor for the Cardinals since exploding onto the scene in 2017. Much of his inflated numbers that year were due to an elevated and unsustainable BABIP of .349. He settled down a little bit in 2018 to post a wRC+ of 103 and has been producing at a similar level this year (104 wRC+), but the improvement is evident.
DeJong has shown some major signs of maturing at the plate. In his rookie season he struck out a lot and hardly walked. Even though he was successful, he may have found his success difficult to replicate unless he improved his approach at the plate. It is very difficult for a hitter to provide above average production without an ability to walk or consistently connect with the ball. Fortunately, he adapted. The next season he dropped his strikeout rate taking more free passes. This underscores an improved approach at the plate that helped him maintain an above-average wRC+ of 103 despite the fact that his BABIP regressed by 61 points. This change in approach can be seen by analyzing the shortstop’s plate discipline metrics that are listed in the table below. He became better at identifying balls and strikes and learned to channel his aggression towards the right pitches not just every pitch. This selectivity allowed him to make more contact on pitches in the zone which led to more than a 2% increase in his hard contact rate and nearly a 3% decrease in his soft contact rate.
DeJong’s Percentages since 2017
This progression has continued in the 2019 season. The 26-year-old has posted an OPS of .784, which is 38 points higher than last year, but this has led to only a 1-point increase in his wRC+ (104) after being adjusted for league standards. However, this is despite a BABIP (.271) that is likely due for some regression to the mean. Many of the reasons for this improvement are due to the continued progression of last year’s developments. DeJong has improved his walk rate even further this year while slashing his strikeout rate by However, curiously, despite walking more, he has swung at more pitches this year. It appears that he has become more selectively aggressive, showing the ability to lay off pitches outside the strike zone while being aggressive on pitches inside the zone. His ability to do this means that DeJong should be able to hit better pitches while still taking more walks. That is the case this year as his power has ticked upwards (.193 ISO in 2018, .211 ISO in 2019) while his walk rate has grown.
However, one danger that is in DeJong’s profile is his lack of line drives. Despite an improved approach at the plate, DeJong is hitting nearly 6% less line drives this season and most of those line drives have turned into ground balls. His ground ball percentage has risen by nearly six percent as well, while his flyball rate has stayed nearly identical (0.1% change). While it is unlikely that a .270 BABIP will be normal for DeJong, part of the blame for his relatively low batting average should go to the decrease in his line drive rate, as line drives, statistically, fall for hits more often than any other type of contact.
DeJong has not just improved at the plate, however. The shortstop has become one of the best in the game at stopping ground balls. In his rookie season, DeJong was average to above average at short. He posted a 3.3 UZR/150 and 0 defensive runs saved. These numbers are not bad, but they are not nearly elite. Last year, in 2018, DeJong made a big jump. He maintained a 9.3 UZR/150 while collecting 14 DRS. He ranked fourth in the majors at the shortstop position in both of these categories, as well as first in the NL. This improvement cemented him as one of the finest defensive shortstops in the game. He has solidified that reputation with his play this season, posting a 9.8 UZR/150 with 11 DRS. This improvement has given the Cardinals possibly the best middle infield tandem in the MLB with DeJong at short and perennial gold glove candidate Kolten Wong manning second base.
DeJong has even improved on the base paths since his debut, posting a BsR rating of -2.4 in his debut season, before becoming an asset in his next two seasons, posting ratings of 2.7, and 1.5, respectively. BsR is an all-encompassing statistic that determines the value of a players baserunning and forms the baserunning component of the WAR calculation. Upon closer inspection, DeJong has actually improved as a baserunner this year, excluding stolen bases. His UBR (Ultimate Base Running), which is a statistic that measures how much value a player adds to their team from their baserunning, excepting stolen bases and caught stealings, has actually improved this season from 1.5 to 3.2 (it was -3.3 in 2017). The only thing dragging down his BsR is a bad success rate on stolen bases (7-for-12). If he could improve his ability to steal bases, or his ability to recognize when he should attempt to, then he could become even more valuable. While not slow, DeJong is not a player who is strikingly fast, so his ability to create value for the team when he is on the base paths is an added bonus that makes it even easier for the team to score runs.
On the surface, it appears that Paul DeJong’s best season was his rookie year and it appears that he has been pretty much the same player as he was last year. However, this is not the case. Much of the success he experienced in his rookie season was due to an inflated BABIP. In the two years since then, DeJong has made some important adjustments that have allowed him to become one of the top shortstops in the league - all while his underlying numbers and progression rate suggest that his best might be yet to come.