2018 MLB Draft Guide Player Profile: Luke Weaver

Luke Weaver

As far as polarizing pitchers go, Luke Weaver could be among the most debated targets in preseason drafts. After a rough debut in 2016, Weaver bounced back to strike out 72 in 60.1 innings last year on his way to winning seven games and rewarding those who either stashed him or made an early waiver claim upon his promotion. Unlike some strikeout pitchers, Weaver benefits from command and owns a much higher strike-swing percentage as compared to chase rates.

Weaver recorded a 69.9 Z-Swing percentage (swings and misses at pitches in the strike zone) which placed him in a tie for 22nd in the second half among pitchers with at least 50 innings. He did finish with a 25.5 chase rate (swings and misses at pitches outside the strike zone) which does not rank particularly high, yet Weaver proved to be effective in spite of this. Looking at his swinging-strike percentage, a slight increase to 9.6 percent and Weaver allowed a contact rate of 79.1 percent last year.

In spite of the high contact, which can be a result of his ability to throw strikes, Weaver finished with a 3.88 ERA, 3.17 FIP and 1.26 WHIP for the Cardinals. He increased his strikeout-minus-walk percentage to 21.8, up two percent compared to his previous stint in the majors. Of more importance, Weaver cut his fly-ball percentage by almost six percent while raising his ground-ball rate by nearly 19 percent. This trend needs to continue for Weaver to hold the gains from last year.

Part of Weaver’s success can be attributed to limiting hard contact evidenced by his hard-hit percentage of 25.9 percent in 2017. In an effort to determine if this can be repeatable, Weaver’s numbers on xSTATS suggest they could. His bbFIP (batted ball Fielding Independent Pitching) of 3.65 just about represents the difference of his ERA and FIP from last year. Plus, his average exit velocity allowed of 85.7 MPH moved down three MPH compared to his debut in the prior season.

Although Weaver does not possess a dominant pitch, at the end of 2017, it seemed like all of his repertoire worked, contributing to his strong season down the stretch for the Cardinals. First, here’s his average velocities while in the majors, note the slight increase last year:

As the season moved on, there’s a slight decrease in the cutter and curve, but the more velocities differentiate, the more success a pitcher can incur. Next, here’s Weaver’s swinging-strike percentages for his career, courtesy of BrooksBaseball.net:

In the September convergence of dots, Weaver recorded a 22.2-percent whiff rate with the fastball, 19.23 percent on the change, 16.67 percent with the cutter and 17.39 on the curve. Again, no dominating pitch, but all generating whiffs per swing. If he’s to continue evolving into a front-line starter, Weaver will need to keep the ball on the ground. His arsenal appears next and pay attention to the ground-ball percentages with his off-speed pitches:

With the knowledge Weaver makes his living inside the strike zone, he needs to maintain ground-ball rates to limit damaging home runs or fly balls. Especially with his high-contact rates allowed. Like many in baseball, he could also benefit from moving just above the strike zone to entice hitters trying to elevate the baseball with a pitch they cannot hit into the air. Weaver’s whiff-per-swing chart in zone profile view illustrates this:

Although the points on Weaver seem to register, BaseballSavant.com added a 3D version of how to see a pitcher’s arsenal in a picture, here’s Weaver’s view from a hitter’s perspective:

Working up in the zone with the fastball to offset his change which shows some drop and the curve on a slightly different plane can work for Weaver this year. Seeing how his evolution as a pitcher continues will definitely determine his value in drafts. Many will not forget his late season value and Weaver does not come cheaply anymore. As for his projections, they seem very similar between Steamer and ZiPS except in regards to innings pitched, which will ultimately determine his ceiling.

Going back to 2015, Weaver logged 105.1 innings which increased to 119.1 across three levels in 2016 to 138 last year between Triple-A and St. Louis. In order to protect his arm, the Cardinals may not exceed 165 innings for him this year, but Steamer predicts him to reach 145 innings with ZiPS being more conservative at 133.2 innings. Wins seem fluky to predict, but Weaver should reach double digits. Steamer forecasts an ERA of 3.81 with a 1.23 WHIP versus ZiPS at 3.73 ERA and a 1.24 WHIP. Realistic, especially when taking into account Weaver’s xSTATS from last year which suggest he could outperform both of these within reason.

As long as Weaver can reach 160 or more innings and he holds the gains in Z-Swing from last year, he could also finish with 155-to-175 strikeouts. It’s a wide range of outcomes depending on how the league adjusts to him plus how Weaver mixes his pitches. Taking Weaver as a third starter with upside makes sense, but asking him to be a fantasy number two could be asking too much.

Weaver’s fantasy worth this year will be determined on where he’s drafted and ultimately how he performs. If he can stay in between his ERA and FIP from last year, he’s worth the risk.

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Statistical Credits:

Fangraphs.com, BrooksBaseball.net, xSTATS.org, MiLB.com, BaseballSavant.com, Steamerprojections.com, ZiPS courtesy of Dan Szymborksi