Edmundo Sosa has a 109 wRC+ on the season. When combined with his strong defense, this has allowed him to compile 1.5 fWAR in just 257 plate appearances. This makes him the 7th most valuable position player on the team despite having almost 170 fewer plate appearances than Dylan Carlson, the sixth most valuable position player. Interestingly, Harrison Bader has a higher fWAR by 0.1 and has just 41 plate appearances more than Sosa.
By all accounts, this has been a great season for Sosa. However, his offensive production is much greater than it was in the minor leagues. In fact his 109 wRC+ is the highest mark of his career since he played rookie-level ball in 2015. This begs the question: can this production be sustained?
Based on minor league history, the answer is no. It is unlikely that Sosa will suddenly show enough improvement to be a legitimate starting-caliber shortstop after being a below league average hitter at pretty much every full season minor league level. However, it is actually possible that some of his improvement can be sustained.
Sosa’s chase rate of 35% is well above the league average of 28.3% and his swing rate of 54.2% is much higher than the league average of 46.9%. This makes it difficult to draw walks, and without a reformed a approach, he is unlikely to increase his walk rate. Despite this, Sosa has managed to post a .353 OBP. This is largely due to being hit by 15 pitches this season. That ranks as the ninth most in the majors, and Sosa has taken at least 115 fewer plate appearances than every hitter above him.
Sosa has actually accumulated more hit by pitches (15) this season than walks (13). With his aforementioned undisciplined approach at the plate, this makes hit by pitches an important stat for Sosa. If Sosa’s hit by pitches and their associated plate appearances were taken out of his stats, then he would have a .314 OBP. This is not bad, but it is certainly worse than his current .357 OBP. A subtraction of almost 40 points of OBP makes a huge difference for any hitter, but especially one with limited power (.130 ISO). If Sosa’s hit by pitches dropped to 7 instead of 15, then his OBP would be .333. Thus, Sosa’s overall production has a degree of dependence on a high rate of being hit by pitches.
Thus, it is important to consider if this can be sustained. This is difficult to determine and it may seem that there should be plenty of variance in how many pitches hit a player on a year-to-year basis as most HBPs are a result of the pitcher making a bad pitch instead of anything that the hitter can control. This is not necessarily true, though, as some hitters at the top of the HBP leaderboard this season have shown an ability to get hit by pitches throughout their careers. For instance, the current leader is Mark Canha with 22. In the shortened 2020 season he was hit 10 times, and in 2019 he was hit 18 times. Obviously 22 is a lot and there is still time left in the season, but 28 HBPs in his last 740 plate appearances is still significant.
Another example is Anthony Rizzo who has been hit 18 times this season and, not counting 2020, has not finished a season with fewer than 15 HBPs since 2013. Jose Abreu (17 HBPs) has posted double digit totals in every season of his MLB career. Victor Robles (16 HBPs) was hit nine times in 2019 and 25 times in 2018. Ty France (21 HBPs) was hit 10 times in 356 plate appearances prior to this season and had a history of getting hit in the minor leagues.
The only player in the top ten without a real history of HBPs is Josh Harrison (17 HBPs in 2021), but even he was hit 23 times in 2017. This seems to suggest that while there is a degree of variance in HBPs, there are some hitters who have an uncanny ability to get hit on a year-to-year basis. This is a good sign for Edmundo Sosa as he is not only somewhat dependent on HBPs, but also has a bit of a history of getting hit in the minors. In 2019, Sosa was hit 17 times (16 in Triple-A, 1 in MLB) and in 2018 he was hit eight times.
It is always possible that Sosa improves his plate discipline next season, but if not then a decent amount of his OBP will be based on his ability to draw hit by pitches. This could be key for Sosa to continue being a productive hitter.
Sosa has actually improved his walk rate a bit from 2019 as he walked at just a 3.4% clip in Triple-A. This is a good sign as such a low walk rate with limited power would really limit his upside at the plate.
In terms of batted balls, Sosa has shown an ability to have decent results when the ball is hit in the air as he has a 117 wRC+ on fly balls. This may not be sustainable, though, considering that his average exit velocity (87.0 mph) is worse than Tommy Edman’s (87.3 mph) and Edman ranks in just the 16th percentile. If Sosa was a qualified hitter, he would likely be in the bottom 15% in terms of exit velocity. He does have a high average on ground balls (.283) and especially ground balls hit up the middle (.316) as he has 98th percentile speed, but his limited power and willingness to hit the ball in the air (51.1% ground ball rate) does limit his offensive profile.
Sosa is still just 25 years old and playing his first full season in the majors. As a result, he could still improve some of the weaker points of his game. Considering his minor league production, though, it is unlikely that Sosa will be able to retain this level of production. He is a hitter who will need to get on base at a decent clip in order to maximize his production since he does not have a ton a power. Given his low walk rate and poor plate discipline, that could be difficult. However, given the possibility of him being able to consistently draw hit by pitches as well as use his elite speed when he makes contact, it is possible that he could be close to a league average hitter with a strong glove. This certainly makes him a valuable player and someone that should have an important role for the St. Louis Cardinals in the future, even if he is not starting.