In case you haven’t noticed, home runs have been on the decline this year. It’s not a decline to the pre-juiced ball era, just yet, but we’re already winding down from a whirlwind 2017 that saw the most home runs in a season ever:
- 2015: 0.027 HR/PA
- 2016: 0.030 HR/PA
- 2017: 0.033 HR/PA
- 2018 (so far): 0.030 HR/PA
This is a trend I’ve already written about, and a phenomenon we should take note of: even though exit velocity, launch angle, and expecting slugging have gone up, even from 2017, we have seen a decline in both home runs and HR/FB%.
So, that has caused not only a decline in the overall number of home runs, but also a decline in home run hitters, which is similar but not exactly the same. Because even if the overall number went down, we would still see some top-level hitters reaching the clouds; instead, we have seen a deflation in the second-half numbers of power hitters. I recently tweeted this...
12 players had more than 20 home runs in the second half of 2017. This year? Just one (Khris Davis) so far, and only five have more than 15.— Beyond the Box Score (@BtBScore) September 12, 2018
...and the first thing you should be is very surprised, and the second thing you should be is incredibly impressed with Khris Davis.
Davis was a seventh round pick in 2009 by the Brewers, and he was acquired by the Athletics for only Jacob Nottingham and Bubba Derby. He’s a one-dimensional-type player, for sure, but he has been paid just $17.5 million and has amassed 12 bWAR.
When you’re his type of player, when power is the one calling card, you find yourself in both a fortuitous era, but also at an inflection point where that fortuitousness may be running dry. And yet, he has continued to prosper:
His hard hit rate and wRC+ have risen each year since 2016, and yet the only thing that has sharply dropped in 2018 is... HR/FB. That would agree with the findings in my previous piece that we’re in a lower home run environment.
How has he stemmed the tide, though? Even though the rate at which fly balls are going out of the park is decreasing, he leads the league in home runs at 41, and he is on pace to hit 45, which would be a career high. To combat the changing winds, the answer is simple: lean in further to his initial strategy.
By launch angle, you can see that the strategy is deliberate:
- 2016: 12.9 °
- 2017: 14.2 °
- 2018: 17.7 °
This isn’t exactly a “strategy,” but he is definitely hitting the ball harder as well:
- 2016: 91.7 mph (average exit velocity)
- 2017: 92.2 mph
- 2018: 92.7 mph
As we saw, the overall environment still resulted in a lower HR/FB ratio despite the higher angle and faster exit velocity, and this is reflected in expected slugging percentage (xSLG - SLG) as well:
- 2016: 0.561 - 0.524 = -0.037
- 2017: 0.583 - 0.528 = -0.055
- 2018: 0.601 - 0.542 = -0.059
His expected slugging percentage is .600 (!), and yet it sits at just .542. There could be something to be said that if he continues to under-perform that there’s a reason as to why, but I find it more compelling that the environment is changing, and he has some bad batted ball luck anyway, so his improved strategy is beating back the tide of that change in environment. I welcome a different hypothesis, as well.
At 135 wRC+, this is about the hitter Davis needs to be to be successful in modern baseball; gone are the days when empty power hitters are granted roster spots when their offensive performance sinks below the necessary thresholds... especially when you’re talking about the Oakland Athletics. Davis could very well finish with the most home runs in baseball, and it’s in large part because as the league for whatever reason suppresses fly balls, his solution is just to hit a ton more of them.