Let’s face it. This MLB season has been highlighted by home runs and home runs alone. Major League offenses connected on 6,105 home runs, obliterating the 2000 season’s previous MLB record of 5,693. Even more impressive is the fact that this season is without the steroid issue that plagued the league 17 years ago. These unprecedented power numbers have been attributed to everything from juiced balls to higher launch angles to pure freak athleticism (see Aaron Judge).
But as history (and statistics) have shown, with an uptick in home runs comes an uptick in strikeouts. In fact, there is a Pearson’s correlation coefficient of 0.96 between the two. This means that the two statistics are almost totally linearly correlated or that in any given season, more home runs means more strikeouts and vice versa.
Seeing as everyone and their mother has chosen to write about baseball’s rising power numbers and stars like Giancarlo Stanton and Aaron Judge, I decided to focus on the equally unprecedented peak in strikeouts.
After peaking at 6.67 per game in 2008, MLB strikeout counts have steadily risen to today’s 8.25 mark. Despite this peak, however, the league batting average of .255 isn’t that far off from the .258 aggregate mark from 1941-2017. It was at this point that I discovered a puzzling dilemma.
The theory that a focus on power leads to an increase in strikeouts is confirmed by the graph above. An increase in strikeouts suggests that hitters are missing more pitches. This, in turn, suggests that hitters aren’t getting as many hits — there is an average of 8.72 hits per game in the 2017 season, down from MLB historical average of 9.1. Ultimately, this heap of data and theories points to batting average taking a hit (no pun intended). So how is it possible then that an increase in home runs and strikeouts correlates with a plateau in batting average?
My first hypothesis was almost too easy. An increase in homers means an increase in power. Pitchers hate giving up home runs and therefore, will try to avoid letting them up. This leads to less ‘middle-middle’ pitches and more that border the strike zone. Ultimately, whether intentional or not, the walk rate should increase with an increase in home run rates. This, in turn, would counter a dropoff in hits by lowering the number of at-bats, resulting in a plateau of batting average.
Here’s a quick math lesson for those who need it. Walks, hit by pitches, and sacrifices, though valid plate appearances, do not count as at-bats. Therefore, if player A has three hits and none of the above qualifiers in 10 plate appearances, he has an average of .300. However, if player B also has three hits, but four walks in 10 plate appearances, he has an average of .500.
However, a quick glance at the graph above shows that in the 150ish years of recorded baseball statistics, there is a correlation coefficient of 0.61. Though this suggests some degree of correlation, the graph above depicts a very haphazard connection between the two statistics.
After mulling over the other ways in which this home run and batting average increase could have happened — sacrifices, hit by pitches, scorekeeping errors — I concluded that there could only be one logical cause. BABIP.
BABIP stands for Batting Average on Balls In Play. The statistic describes what percentage of fair balls turn into hits. Over the course of MLB’s illustrious history, the league has had an average BABIP of .286. The 2017 season saw the 24th best BABIP in the league’s history at .300, the same as that of the 2016 season.
To recap what this sabermetric breadcrumb trail indicates: traditionally, more home runs means bigger swings, leading to more strikeouts and fewer hits. In 2017, however, while more home runs still mean more strikeouts, more strikeouts does not mean fewer hits. This is because players are hitting .300 on all the balls they put in play.
This BABIP plateau can be traced back to the Lucy of this statistic connect-the-dots game. Hard-hit ball percentage. Contact quality is assessed based on the hang time, trajectory, and landing spot of the ball. Though the statistic has only been recorded since 2002, 2017 marked the second highest mark (31.9%) for hard-hit balls since 2007 (32.0%). Not coincidentally, the 2007 season saw the 9th highest BABIP of all time at .303. Perhaps more coincidentally (or not, who knows), it was the last season that Barry Bonds played in the MLB.
This almost makes too much sense. You need a home run swing to hit home runs. Home run swings generate hard contact. Hard contact generates hits. It seems as though 2017 has thrown caution to the wind and literally gone hard or gone home. And more often than not, they’ve gone hard to get home.
So perhaps it’s time to reconsider the supposed mutual exclusivity of power and contact hitting. Maybe players like Joey Gallo (.209 and 39 HRs) are relics of a fading brand of hitter, and guys like Joey Votto (.319 and 36) represent a new paradigm in the game of baseball. Either way, home runs are up, strikeouts are up, and spirits are up.