When the St. Louis Cardinals acquired Paul Goldschmidt, it seemed they had finally acquired the middle of the order force that they were looking for. It did not work out perfectly in the first season, though, as Goldschmidt was good, but he did not reach the same levels that he did in Arizona.
It has been a similar story for Nolan Arenado and the Cardinals. Arenado has been good, and he has been one of the team’s best players, but he has not approached the five WAR seasons that had become customary in Colorado. From 2016-2019, Arenado had four straight seasons with more than five fWAR, including a 6.1 fWAR season in 2019. In 2021, he has been worth 3.9 fWAR. This still places him among the top 50 hitters in the league (46th) and the top 3 hitters on the Cardinals, behind only Tyler O’Neill and Goldschmidt.
This has not been a bad season by any means, and Arenado has played a crucial role in the success of the Cardinals. However, he has not reached his previous levels of production. This makes Arenado’s debut season similar to Goldschmidt’s debut season, and with the way that Goldschmidt has played this year, there should not be much cause for concern with Arenado.
There are similarities between each player’s first season with the team. To begin with, each player had a lower than career average exit velocity, but neither player experienced a drop of more than one mile per hour. While a drop is not good, neither drop was significant enough to warrant much concern. Exit velocities can fluctuate a bit on a season-to-season basis, and Arenado has only experienced a drop of 0.4 mile per hour from his career average.
Despite not dealing with a major drop in exit velocity, both players saw their BABIPs drop well below their career averages in their first seasons. Goldschmidt’s .303 BABIP was 44 points below his career average, while Arenado’s .249 BABIP is also 44 points below his career average. This would be concerning if their had been a major change in contact quality, but there has not been such a change.
There has been a difference in contact type, though. Arenado has pulled more fly balls than ever in his career, posting a career high pull rate and a career high fly ball rate. According to Fangraphs, Arenado has pulled 41.8% of his fly balls, which is over 7% more than his previous career high. On these pulled fly balls, Arenado has posted a wRC+ of .369. This is lower than his average wRC+ of 459 on pulled fly balls from 2016-2019, but it is still strong.
This could explain some of the decline in Arenado’s BABIP. The third baseman has a .137 BABIP on pulled fly balls, which is in line with his career average. A result of hitting more pulled fly balls than ever before, could result in the lower BABIP that Arenado has experienced.
The major change in contact quality that has been experienced by Arenado has come on fly balls hit up the middle or to the opposite field. On these batted balls, Arenado has a wRC+ of -45 and a BABIP of just .082. Both of these are well below Arenado’s career average. Part of the problem is that his hard contact rate has on these batted balls has dropped from 41.2% to 21.9%. While that is certainly not ideal, it likely does not completely explain such a precipitous drop in production. In fact, Arenado has not hit a single home run to any other part of the field besides the pull side. For reference, in 2018 and 2019, Arenado combined for 27 home runs to these parts of the field.
His newfound emphasis on pulling fly balls allows him to have more batted balls with the highest level of production, but it may cause him to lose production on other kinds of fly balls if he is looking to pull most pitches. Even so, it is unlikely that the long term result of this change is a lower wRC+ and a lower BABIP on overall fly balls like it has this season. This may be what Arenado has experienced this season, but it is unlikely to be what he experiences next season.
Arenado’s production on ground balls has been a bit lower than usual, but not worryingly so, and his production on line drives has been around his career average. Thus, the difference in fly ball production in the only major change on Arenado’s batted ball stats.
Arenado’s approach towards hitting fly balls may have lowered his production on fly balls that he does not pull, and that is something that he may have to figure out next year. Generally, though, for someone with the power of Arenado, it is a good idea to pull more fly balls.
He has still maintained a solid exit velocity, and he is still just 30 years old. As a result, it is likely that he will rebound next year, like Goldschmidt did after his first season. This could turn Arenado froma 4 fWAR player into the 5+ fWAR player that he was with the Rockies. Even so, this season has certainly not been a disappointment for Arenado, but some improvement in his fly ball production, specifically on fly balls up the middle and to the opposite field, could have a great effect on Arenado. A little more BABIP luck could help him with this, too, as his decline in BABIP is partially, but not entirely, due to his increased fly ball rate.
Like Goldschmidt, Arenado has also seen his walk rate decline in his first season. From 2016-2019, Arenado posted walk rates above 9.0% every season. This year, he is down to just 7.7%. Goldschmidt also experienced a drop in his walk rate upon joining St. Louis, but it rebounded in the following years.
This could be the result of these hitters tweaking their approaches and their strategies at the plate with a new hitting coach. It also may simply take a year to settle in with a new team. Goldschmidt’s diminished production in 2019 did not last, and it is unlikely that Arenado is now a 4 fWAR player instead of the 5-6 fWAR player that he used to be. As a result, a tweaked approach with a little more patience and some more batted ball luck may see Arenado rebound to his peak levels next season.