Can the Chicago Cubs help Adbert Alzolay become a reliable starter?

This paragraph is unsuitable for younger or more sensitive Chicago Cubs fans. Fangraphs currently projects your 2022 baseball bruins to have a .449 winning percentage. Assuming (heroically) the season consists of 162 games, that means the Cubs would surge from their abysmal 71 wins in 2021 to … uh … 72.7 wins. They might make the postseason if the playoff field expands to 26 teams.

Making a lie of this projection will require a number of things to go right this year. One of the most obvious links in this chain is pitching improvement. The Cubs have already brought in Marcus Stroman and Wade Miley, as well as new front office personnel to turn around the team’s sputtering player development efforts. As Sahedev Sharma reported in The Athletic (subscription required), the Cubs have a new approach  for training their minor league arms  but they will also need to squeeze what value they can from the young pitchers already in The Show, most notably Adbert Alzolay.

Alzolay is fun to watch. He’s animated on the mound and has great offspeed stuff that can make hitters look silly. But last season hitters took some revenge; Alzolay finished with a mediocre 4.58 ERA, 93 ERA+ and 4.65 FIP. Too many of his pitches find the fat part of the bat: according to Statcast, his barrel rate is among the worst 15 percent in all the land. On the other hand, his walk rate was in the top quarter of the league, and his 1.16 WHIP was the Cubs’ best by a magnificent margin. It would have been good for 21st in the majors (right behind Stroman) if Alzolay had tossed enough innings.

So there’s some real talent here, but some rough edges as well. Delve into the numbers a bit and Alzolay’s biggest weakness becomes clear: lefties absolutely pulverized his fastballs last year. The right-hander throws two of them: a four-seamer and a sinker. Lefties didn’t care which; their expected slugging was over .700 against both, with barrel rates around 20 percent. The major league average is around eight percent. Against righties, Alzolay was much better, with expected slugging a bit over .400 and barrel rates of six percent and zero for the sinker and four-seamer, respectively.

According to Statcast, last season Anthony DeSclafani had a slider-heavy pitch mix similar to Alzolay. Lefties hit his fastballs hard as well (hey, it’s what lefties do to straight stuff from northpaws) but not nearly as hard as Alzolay’s. DeScaflani’s four-seamer had a barrel rate of around 11 percent and his expected slugging allowed was around .500. How did he do it?

Chicago Cubs: Breaking down Adbert Alzolay’s late-season improvements

First, he threw a lot fewer sinkers to lefties than Alzolay did. Sinkers made up around 21 percent of Alzolay’s offerings to lefties, while for Tony D it was just eight percent. Second, nearly 35 percent of the pitches DeSclafani threw to lefties were sliders. Alzolay threw just under 30 percent.

Last September, after an August IL stint, the Cubs moved Alzolay to the pen, and he carried out the Tony D pivot. He actually experimented with several different mixes throughout the season, but ended up significantly reducing sinker usage while upping four-seamer and slider rates. The results against lefties were encouraging, if not an unmitigated success. The barrel rate on his four seamers fell to DeSclafani levels, and while Alzolay’s expected slugging was still high for four-seamers, for all his pitches (especially the slider and change) it was better than it had been in July and August.

The standard small sample size caveats apply, as does the fact that Alzolay’s velocities across the board unsurprisingly improved when he moved to the pen. by moving to the pen. As a starter Alzolay won’t be able to keep all the velocity gains he saw last September, but if he can learn to retain even some of that gain while making the other adjustments discussed here, he could help propel the Cubs beyond 73 wins next year. Hey, it’s all about achievable goals.