Kolten Wong (.334 wOBA, .308 xwOBA)
It makes sense that Kolten Wong massively outperformed his xwOBA. The second baseman put up strong offensive numbers for the Cardinals in 2019, but his quality of contact is suspect. He finished in the bottom 2% of the league with an 83.6 mph average exit velocity, the bottom 7% of the league with a 2.5% barrel percentage, and the bottom 6% of the league with a 25.1% hard hit rate. Clearly, none of these numbers are encouraging and they call into question if he will be able to replicate these numbers. Additionally, Wong experienced a nearly 50 point jump in his BABIP from 2018. These numbers seem to imply that Wong was the recipient of some good luck last season. However, there is also a case to be made that he can maintain his above average production at the plate. Wong performed well against the shift last season, has shown an ability to add a couple hits per season by bunting, and has the speed that is necessary to beat out infield singles. These may seem like small things, but they can add a couple of hits over the course of the season and that can have a solid impact on a player’s final stat line. Wong batted .335 against the shift last season and recorded a hit on 45% of his bunt attempts. It is easier for weakly hit balls to become hits if they are hit to the opposite field against the shift. Add in Wong’s ability to bunt and it seems likely that he will be able to record average to above average production despite weak exit velocities. Still, Wong’s weak quality of contact is not reassuring and it will be interesting to see if he can continue to outperform his expected production.
Tommy Edman (.356 wOBA, .330 xwOBA)
Unlike Wong, Edman’s xwOBA and average exit velocity (87.1 mph) were solid despite his over achievement. Even if he cannot replicate his production from last season, his expected numbers were solidly average, meaning that he is likely not as big of a risk for decline as Kolten Wong is. One of the causes of this over performance seems to be a large discrepancy between his wOBACON (.409) and xwOBACON (.375). His wOBACON was actually the second highest on the team among starters (behind only Paul Gldschmidt) while his xwOBACON was seventh on the team among regular players. Much of this over achievement could be due to Edman’s increased power as his .196 ISO in the MLB in 2019 was much higher than his ISO at any minor league level in his career (except for his .208 ISO in AAA in 2019). This surge in power that Edman experienced might have been a bit drastic given his decent but not great exit velocity. This seems to be the largest area of concern for Edman at the plate as it is unknown if he can sustain his power this season and in the future. Even if he cannot, however, he is a solid contact hitter with a lot of bat control (much like Wong), so he can likely experience a drop in power while still maintaining his ability to be at least an average hitter.
These were the only notable overachievers on the team last season. Tyler O’Neill overachieved a bit too but he did not have too many plate appearances and he was not presented with the ability to settle into a role with regular playing time. With these being the only notable overachievers, that means that most players on the roster underperformed their expected numbers. This could be the reason why the front office is relying on internal improvements in order to hit the ball better next season. Time will tell if this was the smart decision, but it seems likely that the Cardinals lineup was impact at a minor level at least by some poor batted ball luck.