What Xander Bogaerts’ Different Approaches Tell Us
A lot of internet ink has been spilled on the Fly Ball Revolution in baseball. Some of it has certainly been done by me, and with the outburst of home runs leading up to this season, it is firmly one of the main themes of the 2017 season. Of course, the idea that a batter should do more to hit the ball in the air, and subsequently more power, isn’t a novel idea; it’s just being brought to the forefront by analysts. At the same time, it’s important to establish that increasing launch angle does not necessarily predicate more offensive success, as concluded in a study by FiveThirtyEight.
This article was inspired by my curiosity in a quote that Red Sox shortstop Xander Bogaerts made in April. I recently used it in an article about Eric Thames in an attempt to demonstrate the perspective players have when making adjustments at the plate. Here it is to refresh your memory:
“I mean in April it’s not easy to hit home runs,” Bogaerts said. “You’re playing in Boston. I know the wall is right there but it’s pretty hard to hit in the cold in general. We’ll hit some home runs, especially when it starts warming up. Looking forward to a lot of home runs from a lot of guys.”
He continues:
“I mean the cold is good and bad for me,” he said. “The good part is that it helps me do a little bit less. My effort level goes down because it’s kind of cold. But when it warms up I start swinging a bit bigger. You feel stronger because of the sun and whatever. The cold is good because I just try to do more contact, don’t want to get jammed or off the end for my hands to feel pretty bad.”
I found Bogaerts’ candid comments to be interesting and wanted to verify if he really is a different hitter in April than he is in a warmer month, like June. Bogaerts has enough batted ball data this month to match his April data, so now is as good a time as ever to begin examining the effects weather might have on his hands, any changes he has made to his approach, and what those results have led to. First, let’s examine the effects of cold weather and warm weather:
As you can see, there are improvements in exit velocity from Bogaerts on both fly-balls and line-drives. Note that while the increase is over 7 MPH on line-drives, the increase on fly-balls — about 3.5 MPH — was much more marginal. At the very least, it seems to hold up Bogaerts’ theory that he would feel stronger due to the sun. Now, with these changes in mind, let’s analyze the changes Bogaerts has made on his launch angle by comparing April and June. First April:
He swung at some batted balls at a launch angle of around 10 or so degrees, which is just fine, except he hit the majority of them around 0 degrees or less. That led to a lot of ground-balls, which we will discuss later. Here’s Bogaerts’ launch angle in June:
That distribution is much more consistent, and this time it is concentrated in the 10–15 degree range that he hinted at in April. Statcast measured his April and June launch angles at 4.2° and 13.2° respectively. Things are sounding good for Bogaerts so far! He is swinging a lot bigger, just as he said he would in April. But what does this mean for his results? It’s easy for us to use the new data from Statcast and automatically assume that players with higher exit velocities and increased launch angles are going to be more successful power hitters. Let’s take a look at how Bogaerts has distributed his batted balls; from what we know so far, we should see a decrease in ground-balls and an increase in fly-balls:
Sure enough, his ground-ball rate has dropped big time. That’s good, but his fly-ball rate has not increased big time. You’ll note that I labelled the statistic “True FB%” rather than “FB%.” This is because pop-ups and other infield fly-balls are included in the original “FB%.” This dilutes the concept that more fly-balls lead to more power, so I removed them from the calculation and counted them separately here. Bogaerts has avoided hitting ground-balls, but in his attempts to hit more fly-balls, he has ended up hitting a lot of weak pop-ups.
It’s incredible that the Bogaerts of April and the Bogaerts of June look like two completely different hitters, but which do you feel is the better hitter? If we use Weighted Runs Created Plus (wRC+), a statistic that encapsulates offensive value, it is the Bogaerts of June, but not by as much as one would assume. He recorded a 96 wRC+ in April, but with all of his adjustments, that number has only gone up to 109. A 109 wRC+ is nothing to sneeze at for a shortstop, but it’s also equal to the number he posted in 2015, a year in which he hit only seven home runs.
Hitting less grounders is good, but that doesn’t necessarily mean hitting more fly-balls is also good. In fact, based on the exit velocity increases in our first graphic, it’s probably in Bogaerts’ best interest to hit more line-drives. Bogaerts knows this, and he has often been a line-drive hitter; that’s why he has recorded a .342 BABIP in his career. None of this is to determine whether Bogaerts is a valuable hitter or not, because he undoubtedly is. However, we have been able to learn from Bogaerts that there are still many ways to be a valuable hitter, and that it’s most advantageous for hitters to simply play to their strengths — whatever they are.
