Since I wrote the 2020 Cubs bullpen primer, Steve Cishek signed with the White Sox, Brandon Kintzler with the Marlins, and it came out that the Cubs are reportedly out on Pedro Strop. Meanwhile, the Cubs have signed only one player to a major league deal, and Steven Souza can’t pitch. Due to budgetary restrictions, the Cubs' front office was tasked with rebuilding a large portion of their bullpen without signing any pitcher to a major league contract. This is a monumental task, but I’m encouraged by the bulk approach they’ve taken thus far. The likelihood that any one of these pitchers individually will be the Cubs' next great reliever is low. However, the odds that at least one of these pitchers will be a good reliever in 2020 seem high.

The Cubs have a mixed track record with high-spin pitchers–spin isn’t a guarantee of success. Just ask Dillon Maples, who had the highest four-seam fastball spin rate last season. Or Carl Edwards Jr., who ranked ninth. The Cubs signed Tyler Chatwood partially because of his high-spin arsenal, to mixed results. However, the team also saw success in 2019, using their new Pitch Lab to Rowan Wick and Brad Wieck into high-spin, high-leverage relievers.

In looking through the pitchers the Cubs have acquired this offseason, a clear pattern emerges: each has an arsenal which consists primarily of a four-seam fastball and a curveball (like both Wick and Wieck), and each has a better-than-average spin rate on at least one of those pitches. In other words, perfect Pitch Lab candidates.

What follows is a look at what the player development staff might see in each of the new relievers the Cubs have signed.

Dan Winkler (Baseball Savant | FanGraphs)

Winkler ranked 21st out of all pitchers in fastball spin in 2019, and had 71st percentile curveball spin. However, to say his results in 2019 were lackluster would be an understatement. Winkler has had the best major league season of any of the pitchers on this list (a 3.43 ERA and 2.76 FIP over 60 1/3 innings in 2018), so it wouldn’t be too surprising if the bounced back from a rough 2019 season without making too many changes. If the Cubs do get him in the Pitch Lab, though, there’s plenty of room for improvement: he reached only 39.7% active spin (the percentage of spin that contributes to the movement of a pitch) on his curve–Wick was at 91.9% last season, and Wieck was at 86.9%. If more of Winkler’s elite spin contributed to the movement of his curveball, it could be a truly devastating pitch.

Casey Sadler (Baseball Savant | FanGraphs)

Sadler split his time between the Rays and the Dodgers in 2019, which could be good or bad, depending on how you look at it–analytically-inclined teams picked him up intentionally, but they also were okay with parting with him. Still, since both of those teams have deeper rosters than the Cubs, it doesn’t necessarily mean that he can’t be a valuable major league pitcher. Sadler has the best spin numbers of any of the pitchers the Cubs have acquired this offseason, ranking 29th in curveball spin, and with 90th percentile fastball spin. Like Winkler, the active spin on his curveball is on the lower end at 60.1%. I would expect the Pitch Lab to look to improve that.

Jason Adam (Baseball Savant | FanGraphs)

While Adam didn’t pitch as well as his 2.91 ERA last season would suggest, he did manage to keep his FIP just below 4.00. Adam ranked 15th in fastball spin, which is elite. Like the other pitchers in this group, he throws a curveball, though there isn’t as much room for improvement in terms of active spin, as he was already at 80% in 2019. Still, Adam’s fastball could play up nicely, and I’m curious as to what the player development staff could do with his secondary pitches.

Tyler Olson (Baseball Savant | FanGraphs)

Olson has a great year in 2017 with Cleveland, posting a 0.00 ERA and 2.41 FIP over 20 innings, then underperformed his peripherals in 2018 with a 4.94 ERA and 3.45 FIP over 27.1 innings. He was worse in more playing time in 2019. So why are the Cubs interested? Although Olson only averaged 87 MPH on his fastball, he also had 87th percentile spin on his curveball. That, combined with the potential shown in 2017 make him a solid depth piece.

Travis Lakins (Baseball Savant | FanGraphs)

Lakins has similar curveball spin to Olson, and 70th percentile fastball spin. The main concern with the former Red Sox is his lack of command, which can be harder to fix. Still, the raw stuff is there, and it’s intriguing.

You’ll notice two newly-acquired relievers missing from this list: Trevor Megill and Ryan Tepera. I omitted Megill due to his Rule 5 status. As for Tepera, he just doesn’t fit into this group nicely. He doesn’t throw a curveball–his most-used pitches in 2019 were his sinker, cutter, and four-seam fastball in that order. While he does have above-average fastball spin, he seems like more of a bounceback candidate than a Pitch Lab candidate. Tepera’s absence from this list isn’t a reflection of his talent–he has a better major league track record than many of these pitchers–but rather of his lack of Pitch Lab potential.

Winkler and Sadler are the most interesting to me due to the low active spin and high total spin on their curveballs–if the Cubs can translate more of their high spin rate into movement, the pitches should become more dominant, and they could translate that into greater success. This bulk approach to relief pitching is risky for a contending team, but it will at least be interesting to see how many of these guys pan out.