Jordan Lyles Thrives in Milwaukee, Again

No team in baseball has been hotter in September than the Brewers. They’ve lost just four games this month and that hot streak has them on the verge of clinching a playoff berth. That they’ve continued to win so many games without their superstar, MVP candidate Christian Yelich, makes their success all the more impressive. But while their offense has managed to find ways to score enough runs without Yelich in the lineup, their pitching staff has been simply dominant.

The Brewers have allowed just 66 runs to score this month, an average of three per game. That’s the fewest runs allowed in the majors and includes a 10-0 drubbing by the Cardinals on September 13. Their team ERA has easily been the best in baseball during this stretch. By park- and league-adjusted FIP, they’ve only been the fourth-best team in the majors, but still the best in the National League.

Surprisingly, their starting rotation has been led by Jordan Lyles. In four September starts, he’s allowed a total of six runs — four of them earned — giving him the lowest ERA of the Brewers regular starters (Brandon Woodruff hasn’t allowed a run in his two starts where he acted as the opener). This string of strong outings stretches back to late July when he joined the Brewers in a trade from Pittsburgh. Since being acquired, he’s been their most reliable starter, allowing two or fewer runs in eight of his 10 starts.

This is the second year in a row that the Brewers have acquired Lyles midseason. Last year they claimed him off waivers from the Padres in August. He made 11 appearances out of the bullpen, compiling a 3.31 ERA and a 2.49 FIP. He wasn’t included on the Brewers’ postseason roster, but his success this year gives him a good chance to be a critical piece for them if they’re going to make a deep run in the playoffs in 2019.

Going back to his time with the Pirates earlier this season, Lyles has made some significant changes to his pitch mix and approach. Here’s a look at how he’s utilized his five-pitch arsenal over the last two years, broken up by team.

Last year, after joining the Brewers, Lyles simplified his pitch mix to feature his two fastballs and his curveball a majority of the time. As a reliever, this approach worked wonders. When he joined Pittsburgh at the start of this season and was inserted back into the starting rotation, he focused his pitch mix even further, ditching his sinker in favor of his four-seam fastball. He’s completely abandoned his sinker in his second stint in Milwaukee and he’s started to throw his slider a little more often.

Emphasizing his four-seam fastball over his sinker is a natural result of focusing on his curveball as his primary secondary pitch. His elevated, riding fastball creates a far more effective pitch tunnel with his diving curveball, particularly against left-handed batters. Using Baseball Prospectus’s pitch tunnel data, Lyles’s fastball-curveball pitch pair has a Pre-Tunnel Maximum Distance (PreMax) of just 1.18 inches when thrown to lefties. The league average PreMax is 1.54 inches. If he starts this pitch pair with his curveball, the tunnel is just as effective (1.15 PreMax). In layman’s terms, this means these two pitches appear around 1.15 inches apart at the decision making point.

Locating his fastball up in the zone and his curveball down gives him an approach that forces the batter to change his eye level. But when he needs to adjust his approach from side-to-side, he’s turned to his slider a little more often. That pitch has above-average horizontal movement for a hard, cutter-like slider like the one he throws. That gives him another weapon to use to neutralize right-handed batters. Since joining the Brewers, the whiff rate on his slider has improved from 15.7% to 26.8%. That increase in effectiveness is likely due to his ability to locate the pitch lower in the zone.

On the left is a heatmap of his slider locations with the Pirates while the Brewers is on the right. There are fewer sliders left out over the plate and more of them are falling below the zone, resulting in more chases and more whiffs.

Lyles is scheduled to pitch tonight against the Reds in Cincinnati. If the Brewers don’t adjust their rotation over their last four games of the regular season, Lyles would be lined up to pitch in the Wild Card game — assuming they don’t overtake the Cardinals for the NL Central division lead. Adrian Houser might be the other option the Brewers could start in a potential Wild Card game. He’s scheduled to pitch the last game of the regular season in Colorado, but he could easily skip that start if needed. Since joining the starting rotation full-time on July 30, he’s posted a 3.52 ERA and a 3.58 FIP in 11 starts. That’s been nearly as effective as Lyles overall, but Houser has struggled a bit in September (5.31 ERA this month). Given the Brewers’ aggressive usage of their bullpen, using Lyles to face the Nationals lineup twice before being lifted might be the most effective utilization of their pitching staff in a one-game playoff.