A Dead Baseball Might Save the Detroit Tigers

Last weekend Major League Baseball sent the Detroit Tigers and every other team a memo about minor changes being made to the baseball. The memo was leaked ($) to Eno Sarris and Ken Rosenthal of The Athletic, and then the Associated Press obtained a copy.

According to the AP report:

"MLB anticipates the changes will be subtle, and a memo to teams last week cited an independent lab that found the new balls will fly 1 to 2 feet shorter when hit over 375 feet."

The obvious goal here is to lower the number of home runs and increase the number of balls in play. This is a reasonable step for Major League Baseball to take, but it’s still shocking to see them actively try to suppress home runs when, for years, the official MLB response to spiking home run totals was essentially “nothing to see here.”

Readers may recall the original home run spike began after the 2015 All-Star game, when baseballs suddenly got bouncier. Ben Lindbergh and Rob Arthur first documented the surge early in 2016, and things only got wilder from there, with balls leaving the yard in 2016 at a rate not seen since the height of the steroid era.

Lindbergh and Mitchel Lichtman first placed blame on the ball itself in 2017, while subsequent research by Dr. Meredith Wills proved fairly definitively ($) that the culprit was lower seams. And then in 2019 Arthur noticed the ball appeared to be juiced again.

MLB hitters blasted 6,776 home runs in 2019, which was 671 more than the previous high in 2017, and nearly 1,100 more than in the year 2000. An MLB study released after the 2019 season concluded the spike was due to lower seams and changes in player behavior.

Home runs were down slightly in 2020, but clearly something needed to be done. MLB’s answer, according to the AP:

"In an effort to better center the ball, Rawlings has loosened the tension on the first of three wool windings within the ball. Its research estimates the adjustment will bring the COR down .01 to .02 and will also lessen the ball’s weight by 2.8 grams without changing its size. The league does not anticipate the change in weight will affect pitcher velocities."

COR stands for Coefficient of Restitution, and basically just means how much of a baseball’s pitched velocity is transferred to its exit velocity after being hit. So MLB batters will be hitting a lighter, less bouncy ball in 2021. But will it really change much?

Practical Effects of a Dead Baseball

If you’re like us, you’re wondering how much of an actual difference this change to the balls can possibly make…and you created a giant spreadsheet to look at the outcomes of thousands of batted balls in 2019. And then you realized there was a much easier way to make a broad estimate. And then you realized you just aren’t any good at physics or statistics.

Or, maybe you’re normal and you stopped at the wondering phase. Our attempted research suggests a potential 2% drop in home runs, or about 140 fewer home runs across Major League Baseball, by 2019 HR rates. The Athletic article cites an analyst who thinks the drop will be more like 5%, or about 340 fewer home runs.

If those estimates are accurate the on-field difference will probably be imperceptible. But we know small changes to the baseball can have a more dramatic effect than anyone expects, and there’s a real-world example as proof.

The Korean Baseball Organization (KBO) made a similar change to their baseballs before the 2019 season, and Sung Min Kim at FanGraphs kept track of the results, which were stunning. KBO home run rates dropped by more than 40%, and the league-wide slugging percentage went from .450 to .385. Batters went from hitting a Super Ball to hitting a loose wad of socks.

It’s unlikely MLB’s changes to the baseball will result in such drastically different outcomes. But what if they do? And what could all of this mean for the Detroit Tigers?

The Dead Baseball and the Detroit Tigers

Detroit fans can be forgiven if perhaps they didn’t notice the skyrocketing home run rates. The Tigers rank 29th in homers hit over the last two seasons with 211. That’s a scant 189 fewer than the New York Yankees.

On the other hand, the Tigers pitching staff allowed the 4th most home runs (341) over the same span. And yes, the gap between Detroit’s home runs allowed and home runs hit was easily the largest in baseball.

The Tigers have taken some steps to add more punch to their lineup lately, signing Jonathan Schoop, Renato Núñez, and Nomar Mazara within the last week. On the pitching side, replacing Jordan Zimmermann (1.45 HR/9) with José Ureña (1.42 HR/9) is basically a wash, but look out if Derek Holland (2.30 HR/9) makes the roster. They may be even more homer-prone this season.

Few teams would see their offense less affected by a dead baseball than the Detroit Tigers, and few teams would see their pitching affected more.

So let’s have some fun now and assume the baseball is drastically different in 2021. Theoretically, a KBO-style reduction in home runs would affect everyone across the board, but not all player profiles are the same.

Trouble may be ahead for the subset of hitters with high strikeout rates and extreme fly ball tendencies. But on the flip side, fly ball pitchers with high strikeout rates may suddenly find their ERAs plummeting.

Do the Detroit Tigers have any such players? Yes, yes they do.

Batters (MLB ranks in parentheses)

Núñez’s ranks are out of 128 qualified hitters over the past two seasons, while Stewart’s are based on 276 batters with at least 400 plate appearances over the last two years.

Both players are already on the razor’s edge in terms of being viable major leaguers. A 5% drop in home runs may be enough to push them over that edge, and a 40% drop would basically end their big-league careers. Catchers Jake Rogers and Eric Haase could also be greatly affected. No one wants to see players lose their jobs, but none of the above hitters figure to be key parts of the Tigers’ future.

Pitchers (MLB ranks in parentheses)

Boyd’s ranks are out of 43 qualified starters over the past two seasons, while Jiménez’s are out of 161 qualified relievers. Skubal only has 32 big-league innings, so we didn’t bother with rankings.

These three are among the most fly-ball heavy and homer-prone pitchers in all of baseball, so a 5% reduction likely wouldn’t make much of a difference. But if we get a KBO ball in 2021, they could all see huge jumps in effectiveness. Similar leaps could come from Holland and Tyler Alexander.

Boyd, Jiménez, and Skubal are three of the most important players in the entire organization right now. All three suddenly becoming more effective would obviously be a huge boon for the Detroit Tigers.

A 40% drop in home run rate seems unlikely, and if it happened most fans and players would be up in arms. But for the Detroit Tigers and their fans, a dead baseball might be the best news in years.