On September 19, 2018, Carlos Santana was in the Phillies’ lineup, playing third base. It was an experiment that sparked speculation about his role in Philadelphia going forward. After all, he had just signed a three-year, $60 million contract. But after Rhys Hoskins had one of the worst defensive seasons by a left fielder this decade, it was clear that Santana’s usage would need to be adjusted. Having him play first — thus relegating Hoskins to the outfield — would not work long term, especially for a team trying to contend.
Santana’s brief stay in Philadelphia was mixed. He drew walks in 16.2% of his plate appearances, hit for power at about his then-career-average, and was about average defensively. With that information, you’d probably think that Santana had a good year, but reality was different. He was BABIP’d to death; no qualified hitter in 2018 posted a lower BABIP than Santana’s .231. His slash sat at .229/.352/.414 with a 108 wRC+, a decent-yet-unspectacular season. He also made headlines this past March when it was reported that, near the end of the 2018 season, he had smashed a clubhouse TV after witnessing his now-former teammates playing Fortnite during games.
The Phillies went on to have a memorable offseason, to say the least. They signed Bryce Harper, Andrew McCutchen, David Robertson. They traded for J.T. Realmuto and Jean Segura. Once all of the dust settled, Carlos Santana was no longer wearing red and white pinstripes. The seemingly tumultuous relationship lasted one season. Santana was back in Cleveland, the same place where he had spent the first eight seasons of his major league career.
It’s been quite the turnaround since; Santana has had a career year in 2019. Into games on Thursday, he is hitting .283/.402/.535 in 629 plate appearances. Considering how much time is left in the season, it’s safe to say that all three of his slash marks will go on to represent career-highs:
Santana ranked third on Jay Jaffe’s list of the most improved position players in 2019, and deservedly so. He was even named to his first All-Star team of his career, starting at first base at his home ballpark in Cleveland. Plainly put, it’s been night and day for Santana when comparing 2018 to 2019.
I went back to Jaffe’s list, and found a fact that is both interesting and unsurprising. Among the non-Carlos Santana position players who ranked within the top 10, the average age was 25.7. That shouldn’t come as a shock to anyone; young players are those most likely to improve. It’s just how the aging curve works. Players in the 25 to 27 range tend to be hitting their peaks, so it makes sense that the players in that rough age range tend to be the most improved.
Santana, on the other hand, is 33. Once we add his age back in, the average moves to 26.4. It is true that he is not an outlier among the top-10 players by the Interquartile Range Rule. But, he is still noticeably different from the rest of the field; the next oldest player is DJ LeMahieu at 30.
Even considering Santana’s age, it doesn’t appear that this year is a farce. It is true that he is experiencing some of the best batted ball luck of his career — his .291 BABIP is his second-highest single-season mark, and the 22-point spread between his wOBA and xwOBA puts him in the 62nd percentile among “lucky” hitters. But it is also true that Santana has never consistently hit the ball this hard. His 92.0 mph average exit velocity on batted balls is by far his highest in the Statcast era, and with that, his 10.3% barrel per batted ball rate represents a career-high.
The explanation for this is simple: Santana has improved his already-great plate discipline. He has become even more selective when he swings. Over the past year, his O-Swing rate has been cut by three points, while his Z-Swing rate has increased by one point. This may not sound drastic on the surface, but it is. What has resulted is the largest difference between Santana’s Z-Swing and O-Swing rate of his career:
This does not fully explain why Santana has been so good this year, though it does relate. Having a large difference between one’s Z- and O-Swing rates does not necessarily lead to success. In fact, there was only a weak correlation (r=0.24) between the difference in a hitter’s Z- and O-Swing rates versus their wRC+ when tested among all hitters with 200 or more plate appearances this year. This makes sense, though. If a hitter swings at 100% of pitches in the strike zone, they’re going make weak contact on (or swing through) many “pitcher’s pitches.” A hitter still needs to be selective on pitches within the zone; there’s a balance that needs to be had, and I’d argue Santana has found that balance.
How’s this for a stat? Santana has a higher xwOBA on pitches outside of the strike zone (.412) than he does on pitches inside the strike zone (.355). Take a look at his year-over-year swing rates on pitches within each attack zone:
|Attack Zone||2019 Swing%||2018 Swing%||Difference|
Santana has managed to swing at almost exactly the same rate at pitches in the Heart of the zone, those that he’s most likely to drive. He’s cut his Chase swing rate by 3%. That’s extremely impressive. Almost a quarter of all swing and misses generated by pitchers this season have come in the Chase zone, and over 50% of all swings at pitches in the Chase zones are whiffs. Any generic hitter is likely to swing-and-miss in the “Chase” zone. Santana’s 11.3% Chase swing rate is the ninth-lowest among the 231 hitters to see at least 300 pitches in that zone. That’s pretty solid.
This doesn’t fully explain why Santana has been better on pitches inside the strike zone, though. He’s about as selective on pitches in the Heart in 2019 as he was in 2018, and yet his exit velocities have spiked all across the zone. As Jake Mailhot noted in this piece from June, a swing adjustment might be driving his success.
And here’s 2019:
As Mailhot noted at the time:
Santana is definitely standing more upright in his stance, and he’s much quieter with his body this year. With a big leg kick and a swing that looks max effort every time, all that extra movement with his hands was extraneous. In comparison, everything looks simplified this year. It seems like he’s focused on making hard contact no matter where the pitch is thrown while still maintaining control of his swing. He’s still capable of pulling the ball in the air to generate power, but he’s become a more complete hitter by selectively using that approach instead of selling out for pull power all the time.
What’s interesting is that in the time since Mailhot wrote his piece, Santana has completely changed his tendencies. Prior to Mailhot’s article on June 13, Santana had a 38% pull rate. Since, his pull rate is 51%, while homering 20 times in the 348 plate appearances. His ISO has increased from .244 to .260. In the last few months, Santana has put it all together. He’s tapped into his elite discipline, used his simplified swing to generate more power, and pulled the ball to hit homers.
After a rough season in Philly, Santana seems to have connected all the dots in his return to Ohio. You might not think of Carlos Santana as one of the most improved hitters in baseball — especially coming off of a 108 wRC+ season — but that is exactly what he is.
Devan Fink is a Contributor at FanGraphs. You can follow him on Twitter @DevanFink.