The new bat tracking metrics on Baseball Savant are an excellent tool to implement in our evaluation of hitters. Bat speed is king for hitters, as velocity is king for pitchers. Hitting the ball hard in today’s era of baseball is more important than ever. There are always outliers, but a player’s batted ball data describes his upside. With an influx of data on the pitching side over the last decade plus, we now have some shiny new tools to look at for hitters.
With a full season of data under our belt, we can observe players who made changes throughout the year. How much of it can be applied practically to fantasy baseball is still to be determined. But we can, in the meantime, look at some hitters who improved their bat speed over the course of the season and speculate what that could mean.
Jarren Duran (22.07 ADP)
Duran has already cemented himself as a top-round selection in fantasy baseball with a well-rounded profile. A longtime top prospect, he broke out in 2024, popping 21 homers to go with 34 stolen bases and a healthy .285 AVG. That combination is pretty rare as there have only been 16 such players (20+ HR, 30+ SB, >/=.285 AVG) to attain those marks in a season since 2015.
Duran improved his bat speed by 1.9 mph (72.8 → 74.7) from the first half to the second half. Further, he was among the biggest risers in Fast Swing Rate (27.6% → 48.5%). The 28-year-old has posted high-end MaxEVs in the big leagues. His 112.6 mark in 2023 was in the 82nd percentile, and he upped that mark to 113.9 in 2024, ranking in the top 10 percent of the league.
There are plenty of players that have upper-echelon MaxEVs and don’t produce big power numbers because of their batted ball distribution (see Yandy Díaz). It is possible that Duran falls in this bucket, and his home run totals will be capped around the low 20s. Furthermore, Duran doesn’t have as extreme GB rates, and we have multiple years of evidence with Diaz. And, like Diaz, Duran hits the ball really hard.
Duran’s current all-fields approach has been effective for him and contributes to his AVG staying high. While incremental, he did increase his FB% by 2.1% to over 35%. While Duran’s pull rate will not reach the same heights, there are similarities in career batted ball data to that of Julio Rodríguez.
The clear differntiator is Pull%, and that, along with his park-sapping left-handed power, will hold Duran back from mirroring Rodriguez’s HR outputs. Even if it’s just by a hair, there could be more than 20 HRs in Duran’s future in addition to his other strong traits.
Masyn Winn (160.43 ADP)
Winn had a promising rookie season, showing categorical balance in his profile. He contributed 15 homers and 11 stolen bases to go with a .267 AVG. He hit 10 of his 15 homers in the second half of last season. Winn is an exciting young shortstop with an intriguing skillset of power, speed, and contact. Only 22 years old; there is room for him to grow.
Winn’s bat speed improved from 69.6 to right around league average at 71.1 in the second half. He almost doubled his Barrel% (2.8% → 5.4%) and nearly tripled his Fast Swing Rate (6.9% → 17.4%), all while maintaining his sub-20% K rate. He has a balanced batted ball distribution with flashes of higher pull rates in the minor leagues. With his around league-average raw power, he should consistently settle into the 15-20 range for home runs.
The improvements at the plate in the power department elevate the ceiling for Winn. With his elite defensive ability at a premium position, there is obviously no concern about playing time. And for what it’s worth, he went on record stating his intent to steal more bases this season. With his 87th percentile sprint speed, perhaps there is more meat on the bone for steals if he has the green light. That could make him a possible 20-20 candidate to go with a solid AVG.
Michael Conforto (312.46 ADP)
Conforto enjoyed a bounce-back season in 202,4, reaching the 20 home run mark for the first time since 2019. Everything under the hood looked promising for the 32-year-old. His 11.8% Barrel rate was his best since 2017, and his 45.8% HardHit rate was his best since his rookie year in 2015. He is now almost three years removed from his shoulder surgery, which can be scary for hitters. His 113.6 MaxEV in 2024 signals that he appears to have recovered from that injury.
Conforto improved his average bat speed by nearly two ticks (73.2 → 75.1) and his Fast Swing Rate significantly (30.9% → 55%). His second half bat speed of 75.1 would have been a top 25 mark in baseball among qualified players. In addition, he has proficiently pulled the ball throughout his career and was in the 75th percentile in 2024 for Pulled Flyball%.
If he can maintain that level, his new environment could supplement his power production. In terms of park factors for home runs, Conforto is going from one extreme to the other. Oracle Park is bottom 3 in baseball for left-handed home runs. Meanwhile, his new home in Dodger Stadium is sixth in baseball for lefty power.
Tie everything together, and we could see a mid-20s home run output for Conforto this season. The 33 home run mark in the rabid ball year is an outlier, but he hit 27 and 28 home runs in the two years prior. And another year further removed from shoulder surgery gives more optimism.
Miguel Amaya (443.07 ADP)
Amaya’s 2024 season was a tale of two halves. He was brutal in the first half of 2024 with a slash line of .201/.266/.288 (60 wRC+). Bad luck plays a factor, but his underlying metrics didn’t paint a super-encouraging picture either. A sliver of hope to cling onto for him in that time was a solid 21.5% K rate and above-average defense to keep his playing time afloat.
Amaya made big strides in his bat speed from the first half to the second half (72.4 → 73.5) and in his Fast Swing Rate (26.9% → 39.2%). Those improvements, in part, led to a modest but improved 5.9% Barrel rate and a much improved .271/.316/.444 slash line, good for a 113 wRC+. Impressively, he also cut his K rate from 21.5% to 11.4%.
With no options remaining and strong defensive metrics, Amaya should be the primary catcher for the Cubs in 2025. His ability to consistently make above-average contact is a solid place to start. Further, he has posted double-digit walk rates throughout his minor league career, although that has not translated to the majors. He made a noticeable adjustment to his swing, ditching the high leg kick in favor of a toe tap. The results, albeit in a smaller sample, speak for themselves. This change sheds a positive light on what Amaya could look like over a full season.
Gavin Lux (443.10 ADP)
Lux was a part of a crew of contact-oriented hitters that had a poor first half and decided to simply swing harder to find power in the second half (see this excellent piece by Mike Petriello). Lux perhaps had the most dramatic swing in results of the group. His first half was pretty sad as he was one of just three regular players (min. 250 PA) with a SLG below .300. Conversely, his second half was bonkers as he posted a 152 wRC+, good for 13th best in baseball in that span.
Obviously, that version of Lux is not sustainable. But his improved bat speed (70.6 → 72) played a big part in his resurgence. He doubled his Fast Swing Rate (10.7% → 20.8%) and subsequently increased all of his quality of contact.
Yes, the BABIP was incredibly high, inflating some of his results. And the 10% Barrel rate is unrecognizable compared to his other seasons. This approach change to seek out power more aggressively got met with a 25.2% K rate, which would be his highest since his rookie year.
While this was clearly a worthwhile trade-off in the short term, it’s reasonable to think about the possible downside when the good fortune wears off a bit. His MaxEVs over the years have been underwhelming, with a career high of 109.8. The raw power just seems a bit less believable.
On a more positive note, perhaps he is beginning to tap into more power as he ages into his prime years. In addition, he now gets the luxury of playing in Great American Smallpark, which is the best park for lefty homers by a good margin. His lower ADP indicates that there is not too much belief that his strides are legitimate, which I tend to agree with. But it is low enough to be a good value because the playing time should be healthy on a Reds team that was 26th in wRC+ last season, and a hitter-friendly ballpark always helps.