Batted Ball Data and the 2018 Rookie Class

It’s been a banner year for rookie players in 2018. This season we’ve seen the graduation of the minor leagues best all-around prospect (after the obligatory service time manipulation), a two-way phenom contribute on the mound and in the batter’s box, a 19-year-old that began the year in A-ball, and the Yankees continue to profit from their embarrassment of riches.

Ronald Acuna Jr., Juan Soto, Shohei Ohtani, Gleyber Torres and Miguel Andujar have all broken out. The rookie class has been a treat to watch for any baseball fan, and has likely lead to big fantasy dividends to any fantasy owner who was able to draft or pickup these hitters.

Aside from the production, these rookies have also excelled in many quality of contact metrics.

 

Juan Soto

If you were to look at plate discipline numbers alone, the teenage Soto looks like the most polished and complete hitter. Soto has posted a wRC+ of 145 and an on-base percentage of .411 while hitting 15 home runs since his May call up. But using batted ball data, Soto is striking the ball with less authority than other breakout rookies on the list. His soft contact rate is over double that of Shohei Ohtani and nearly twice as high as Ronald Acuna Jr. And unlike Miguel Andujar and Gleyber Torres, he isn’t keeping the ball in the air – Soto’s groundball rate of 50.4 percent is sixteenth highest in baseball for batters with 150 plate appearances. Soto’s home run to fly ball rate is also nearly twice the league average at 22.4 percent. While 22.4 percent is high, he did post rates above 20 percent throughout his (brief) minor league career.

Soto’s hard hit and barrel rates suggest he may see his power regress (although it should be noted his xwOBA xSLG are not significantly lower than his actual numbers). Despite a potential lag in his home run totals, his ability to control the strike zone makes him more valuable in points leagues, and his inability to run means he is less valuable in roto.

Soto is still poised to be an outstanding hitter and a fantasy asset. And one that hits for at least some power, but depending on format, you may want to consider the others over him.

Ronald Acuna Jr.

Acuna Jr., the consensus top prospect in baseball coming into the season, is hitting the ball harder than any other rookie on this list. Acuna Jr.’s average exit velocity of 90.9 miles per hour is top-50 in baseball (37) and he ranks sixth in baseball in barrels per plate appearance at 10 percent.

He’s also hitting the ball in the air with regularity (40.8 percent of the time). If there is a cause for concern, Acuna Jr. has struck out at a 26.1 percent of the time this season – although his second half rate of 21 percent  indicates that he may be making adjustments as he acclimates himself to big league pitching. While there is swing and miss in Acuna’s game, his ability to hit the ball hard consistently suggests his power is not a mirage and that he is able to do damage whenever he does make contact. He might not hit seven homers in a month, let a lone a week, but Acuna Jr. is a legit power threat that could see gains in batting average if he is able to sustain his reduced strikeout rate.

The most intriguing part of Acuna’s game for fantasy is his 11 stolen bases (14 attempts) in 79 games. If Acuna continues to run successfully at this rate, his potential to provide 50 home runs plus stolen bases makes him a very valuable commodity in any kind of rotisserie league.

Gleyber Torres

Despite missing most of the 2017 season after undergoing Tommy John surgery, the 21-year-old has enjoyed a very productive rookie season. Torres has slashed .269/.339/.495 with a 123 wRC+ and 20 home runs in 93 games with the Yankees this year.

Torres has done this while posting slightly above league average hard and soft contact rates. His exit velocity and barrel numbers are also above average. Torres has seen his walk rate drop and his strikeout rate increase since arriving in the major leagues, but it’s not unrealistic to assume that the youngster could continue to develop as a hitter and hit closer to the .285 he posted across five minor league seasons.

We’ve seen his power (and home run to fly ball rate) spike this season, but given he could be aided by his home park, Torres power gains are somewhat sustainable. He likely won’t be able to hit as many home runs as Acuna, or Ohtani but as a middle infielder who will have shortstop eligibility again next season, he may not have to.

Miguel Andujar

Andujar is the least heralded of the 2018 rookie class but he has been an important part of the Yankees’ offensive dominance this season. Andujar has slashed .301/.332/.526 with a 129 wRC+ and 21 home runs in 120 games .

Interestingly, Andujar’s batted ball data is strikingly similar to Juan Soto’s. They posted very similar soft/hard contact rates and both players own average exit velocities around 89 miles per hour.

Where Soto and Andujar differ is in their plate discipline. Andujar both strikes out (17 percent) and walks less frequently than any hitter discussed. His 4.1 percent walk rate is 10^th lowest amongst qualified hitters. Andujar’s groundball rate (46.1 percent) is also far closer league average than Soto’s. With a minor league high water mark walk rate of 7.2 percent in A-ball, Andujar will never likely be a big on-base threat. His ability to put the bat on the ball mitigates these issues but it does make him a less complete hitter than some of the other rookies.

Shohei Ohtani

Shohei Ohtani’s .276/.345/.547 slash line along with a 146 wRC+ and 15 home runs have quieted critics who believed his pitching abilities were far more advanced than his offensive ones. He’s even thrown in six stolen bases.

Ohtani has been making elite contact. He ranks 15^th in average exit velocity (92.5 mph) and 9^th in barrels per plate appearance (9.6). There is nothing that suggests he shouldn’t be able to keep up his current pace of production.

But there are two major issues that could affect Ohtani’s value as a hitter moving forward in fantasy.

Ohtani has seen time on the disabled list due to a UCL injury in his pitching elbow. An injury that seems to be getting worse – Ohtani suffered a Grade 1 UCL sprain in 2017 and this summer he was placed on the disabled list after being diagnosed with a Grade 2 UCL sprain. Ohtani has been trying to avoid Tommy John surgery, opting to use rest and plasma injections to repair his UCL, but given he is only 24-years-old and has shown the potential to be an elite pitcher when healthy, he may ultimately end up under the knife at some point.

The second issue is that Ohtani has yet to demonstrate he is capable of hitting left-handed pitching. Ohtani has slashed just .167/.265/.233 with a 36.8 percent strikeout rate in 68 plate appearances against lefties. In addition to benching the two-way phenom the days before and after he pitches, the Angels also seem to sit Ohtani against tough lefties as well.

Ohtani might be the second best hitter (for fantasy purposes) on this list but until we know he is going to be healthy and given the playing time to work out his issues against lefties, his offensive potential may not be realized.

Looking at batted ball data I would be most excited about Ronald Acuna Jr. moving forward. And that is before you account for his ability to contribute stolen bases. Juan Soto is a tremendous hitter, but one that may be more suited to points formats. Andujar and Torres may be more likely to contribute in average than Acuna Jr., but their quality of contact suggests Acuna Jr. might have the higher offensive upside. Ohtani is a bit of a wildcard – he has shown underlying skills that suggest he can be elite, but with his health and usage in question, he is a risk right now, especially in anything other than daily leagues.

These are all talented, top-100 hitters. And given they are all under 25 with less than 600 major league plate appearances to their respective names, skills development is likely in the cards.

This rookie class should continue what they started this season and provide plenty of top tier fantasy value moving forward.