Looking back at Justin Verlander’s home run complication and a possible relation to four-seam usage

All in all, Justin Verlander’s 2019 season was a smashing success, at least when it comes down to individual performance. Not only did he throw the third no-hitter of his career, and his first since 2011, the veteran starter won his second Cy Young award. By the numbers, there were only a handful who could claim to have been better in the majors. While it was arguable that former teammate Gerrit Cole was the more dominant pitcher by season’s end, and perhaps more deserving of the AL version of the award, Verlander’s overall body of success last year was impossible to ignore.

But the results are only part of the story. In fact, similar results across multiple seasons could mask something of singular interest. There is a lot of stuff under the hood, per se, that we can utilize to analyze players. Sometimes we won’t notice that much of a change between one season to the next. Other times there is possibly something of substance worth noting. Heck, we could find a change interesting that may fall somewhere in the middle. In regards to Verlander, there are a couple of things worth watching in 2020.

Item of Interest: Four-seam fastball usage

In 2018, there was only one qualified starter in the majors who threw a four-seam fastball at a higher rate than Verlander and his 61.2 percent: Sean Newcomb of the Braves at 62.8 percent. This is frankly not a surprise when one considers that Verlander consistently flirted with a four-seam usage rate in at least the high fifty percent range for most of his career. Before last season, we’ve never seen his four-seam rate fall any below his career-low 56.2 percent back in 2014. But last season we saw Verlander’s usage drop to a noticeably lower rate of 49.8 percent. Notable for him, anyway.

For context, the two-time Cy Young winner still finished seventh in four-seam usage rate out of all qualified starters in 2019. That rate is still quite high when examining the entire starter landscape for last season. Still, the decline when viewed through only the lens of his own past results is rather curious.

Another Item of Interest: The surge in home runs allowed

We all know that home runs have recently become a bit of an issue for some pitchers, which is likely thanks to, in part, how the actual baseball is constructed by Rawlings. By the way, you know who partially owns Rawlings? That’s right, Major League Baseball, who is a co-investor in the company. It is worth noting about the applications of technology and its impact on how hitters can better perform at the plate. But the spike appears to be predominantly associated with the construction of the ball. Home run totals across the league, for example, underwent a noticeable spike between 2018 and 2019. The spike is even more pronounced when one views the totals and home run-to-fly ball rates since 2015.

I dug a bit deeper into the number of four-seam fastballs that were converted into home runs since 2015 to see if there was a notable increase.

It is clear from the get-go that the 2019 season saw the largest increases in home runs via a four-seam offering, which is also one of the two seasons (see: 2017) when the “juiced” ball was widely believed to be at the height of its prowess. The home run-to-total pitch rate only slightly jumps from the previous seasons average to 2019, but it is still worth pointing out the increase seen across the league.

So, how does this tie into Verlander, who has been somewhat susceptible to home runs in recent seasons? Well, for one, the Astros’ ace allowed thirty-six home runs in 2019, which is easily a career-high for him. Only Mike Leake and Matthew Boyd allowed more home runs last year. Twenty-four of those home runs were generated off of Verlander’s four-seam fastball, which also represents another career-high for the right-hander. Yes, the same pitch we saw the usage rate dip to a new career-low. It is reasonable to speculate if this departure in four-seam usage was partially due to a sudden proneness in allowing home runs as the season went along. For example, if we look at Verlander’s four-seam rates on a game-by-game basis, we can see more of roller coaster effect, especially in the season’s second half through October.

The change in pitch usage was likely due to a barrage of factors. Verlander is a constant tinkerer of his craft and changes are always possible, even if unexpected. In fact, his home run-to-fly ball rate through the season noticeably dropped between the first half (18.7 percent) and the second half (11.6 percent). That decrease also lines up with the overall change in four-seam usage, which topped out at roughly 54 percent in April and never cracked the 50 percent at any point during the season’s second half. His lowest rate for the season actually occurred in September at 46.7 percent. That was also the same month where he allowed just two home runs via his four-seam. Thanks to the opinion he expressed last summer that the “juiced” ball was responsible for the home run spike last season, it isn’t difficult to create a superficial correlation in one’s mind between his four-seam’s usage and the effect that the surge in the long ball may have had on his arsenal. Of course we aren’t always aware of the specific reasons behind a pitch change and that could also be the case here.

Without getting into the nitty-gritty behind the physics and makeup of the baseball, it will be interesting to see if the ball this year further alters how pitchers use their arsenals across the league. After all, a pitcher is likely more liable to alter his course of action if certain details are stacked against him. The ball and how it flies off the bat is no different. But say if the ball is less “juiced,” could we see Verlander’s four-seam usage return closer to previous levels? Or was this change unrelated to the baseball? The 2020 season may give us our answer.