Divergent Exit Velo Trends Help Explain Why Kyle Tucker Should Be Improvement Over Cody Bellinger
First things first, I’m operating under the assumption that Cody Bellinger is eventually traded and that Kyle Tucker then serves as a replacement/upgrade. There’s always the possibility that both are in Chicago for at least the first half of the 2025 season, in which case we don’t really need to compare them. But for the time being, we’re looking at how the two left-handed hitters differ in terms of their batted-ball results.
As simple as it would be to look at their stats and see how a guy who put up 4.2 fWAR in just 339 plate appearances is better than someone who generated 2.2 fWAR in 569 PAs, I want to dig deeper. Both Tucker and Bellinger struck out at less than a 16% clip and both had BABIPs that were within five points of one another this past season and differ by just one point on a career basis. One area of disparity comes in walk rate, where Bellinger has failed to reach double digits since 2020 while Tucker has seen improvements in all five seasons as a regular.
Among 286 MLB hitters with at least 300 plate appearances in 2024, Tucker’s 16.5% walk rate and .408 OBP trailed only Aaron Judge (18.9%, .458) and Juan Soto (18.1%, .419). Mike Tauchman led the Cubs with a 13.4% walk rate and Seiya Suzuki paced the team with a .366 OBP last season, but you have to go back further to find closer comps to Tucker’s recent performance. Kyle Schwarber‘s 15.3% walk rate in 2018 and Kris Bryant‘s .409 OBP in 2017 represent the team’s best marks over the last decade.
But the Cubs didn’t pull off a 3-for-1 trade to pick up a potential rental star just because he gets on base. Tucker also finished third behind Judge (.379) and Shohei Ohtani (.336) with a .296 ISO that no Cub has exceeded since Sammy Sosa (.306-.409 in five different seasons) and Derrek Lee (.327 in ’05). Bellinger put up a .315 ISO as a rookie in 2017 and .324 during his MVP campaign two years later, both significantly higher than the .218 during his rebound year with the Cubs in 2018.
Tucker is only about a year and a half younger than his counterpart, but their divergent trends suggest he can continue to improve while Bellinger may be heading in the other direction. This is where we finally turn to the batted ball data, where Bellinger’s 69 mph bat speed last season was in the 13th percentile while his 87.8 mph average exit velocity was in the 23rd percentile. He squared the ball up well with a 30.6% rate that put him in the 89th percentile, but he simply didn’t hit the ball hard enough.
The newest Cubs star swung the bat 72.1 mph last season and squared it up 30.1% of the time, resulting in a 91.1 mph exit velocity that ranked significantly higher than Bellinger. I can’t say for certain because Baseball Savant doesn’t apply percentile ranks to unqualified hitters, which Tucker was due to missing about half the season with a lower right leg injury. Still, his historical results suggest the EV was very much in line with what he has done and will do.
Now, you might be wondering to yourself whether a mere 3.3 mph of exit velocity really makes a difference. The short answer is that it most certainly does based on an estimated 4-6 feet of additional ball flight for each tick of EV. That could mean an extra 13-20 more feet on a line drive or fly from Tucker versus the same hit from Bellinger. Statcast goes with the lower end of that estimate, as most batted balls aren’t squared up and thus won’t get optimal results.
Hitting the ball a few ticks harder also yields improvements of 14 points in batting average and 13 in wOBA, though that is launch angle-agnostic. Tucker’s 21.2 LA last season was more than 2 degrees higher than in any previous season and would typically produce slightly lower results than balls hit at Bellinger’s 17.4 degrees, but that doesn’t factor in exit velocity. See below for simple visual references to get an idea of how Tucker’s average batted ball varies from Bellinger’s.
Again, the oversimplification leaves out the possibility of either home runs or grounders, which is neither plausible nor desirable. As you can surely understand, however, Tucker hits the ball harder, higher, and farther more frequently and will thus be better equipped to put up numbers even if that pesky lake breeze blows in more frequently.
My last note here is that Tucker used the opposite field quite a bit more in ’24, just over 32% of the time compared to Bellinger’s career-high 23.6%. Though the well in left would have cost Tucker a homer at Wrigley, the cozier power alley in left-center would have given him four more. Bellinger hit no homers to the left of the 368 mark and only had three to the left of right-center. A stronger all-fields approach will only accentuate Tucker’s superior results in the areas we looked at earlier.
We’ll have to wait a while yet to see how this works in actuality, but I like it on paper.