25 May 2017

Chris Davis Needs To Swing Smarter

Chris Davis is having a good, but not great year. His .238/.350/.464 line is good for a wRC+ of 119 and has him on pace to be worth 2.7 fWAR. These are good numbers, but not the elite numbers that Davis has put up in the past and that fans perhaps were hoping to see. It is possible to blame his lack of production on his increasing walk and strikeout rates. With a strikeout rate of 36%, Davis is on pace to have the highest percentage of strikeouts in a season for his major league career. His 14.4% walk rate is also the highest of his career, but doesn’t nearly make up for the strikeouts. Remember, Chris Davis crushes the ball when he puts it into play, so he benefits by doing it as much as possible.

A number of people believe that he’s struggling due to his low swing rate. He’s only swung 42.3% of the time in 2017, compared to 49.1% of the time over his entire career. It’s pretty clear that a batter can’t put the ball into play unless he actually swings at pitches. Is Chris Davis’s low swing rate causing him to struggle?

For starters, it is worth noting that his z-swing (swings at pitches in strike zone) is 51.4% while his o-swing (swings at pitches out of the strike zone) is at 35.2%. That’s a difference of only 16.2% between his z-swing and o-swing compared to his difference of 22%. This suggests that not only is he swinging less, he’s also swinging at worse pitches.

I’ve written previously about how batters typically have better results when they swing at pitches in the strike zone compared to when they swing at pitches out of the strike zone. They do a better job putting the ball into play and typically do significantly more damage when they do put the ball into play. In addition, Eli Ben Porat wrote an article awhile back discussing how distance from the center of the strike zone has a correlation with batter performance. This means we can measure Davis’ performance by looking at his swing rate, ball in play rate and wOBA in play rate based on distance to determine whether he should swing more often and where his performance is degrading.

It turns out that distance from the center of the strike zone does have a significant impact on hitter performance. But it’s also the case that it’s easier to understand the effects by putting the data into categories rather than looking at linear models. This is because distance doesn’t have an impact on performance right away. It’s just as easy (and maybe even easier) to hit a pitch that’s .4 feet away from the strike zone than .2 feet. Distance doesn’t begin to really become a factor, at least for Chris Davis, until a pitch is about .5 feet away from the strike zone. After a bunch of testing, I was able to split the data into eight unique bins. These bins are very probably player-specific, so it’s possible that hitters with better range would have different bins. The chart below shows Chris Davis’s performance for 2013-2017.

As the data shows, with the exception of pitches that are between 2 and 2.25 feet from the strike zone (Davis swung at 93 of these, whiffed at 82 of them while putting 2 into play of which 1 was a single), production decreases significantly based on distance. Chris Davis has above average results when putting pitches less than .95 feet into play, average results when putting pitches between .95 to 1.15 feet into play and below average results for anything past that. This suggests that in an ideal world, he would swing solely at pitches in the first two bins and at pitches in the third bin only when there are two strikes.

The data also show that he doesn’t live in an ideal world. While his swing rate decreases based on distance, he still doesn’t always swing at pitches in the first two bins while he does swing at pitches in the last three bins that he’s unlikely to hit or be productive when putting into play. However, he does historically swing at the vast majority of pitches in those two bins. It’s very possible that a more sophisticated analysis that takes pitcher hand, spin, perceived velocity and other relevant variables into account may show that the pitches in those bins he doesn’t swing at are harder to hit than just distance would suggest. It’s also possible that it’s hard for Chris Davis to hit a fastball down the middle if he’s expecting a curveball on the outside corner.

In addition, even when he does swing at pitches in the first two bins, he only puts them into play roughly 35% of the time. Chris Davis may be very successful when he puts the ball into play, but he struggles to do so even when swinging at appropriate pitches. This shows the challenges of putting even clear strikes into play, and hence explains why sluggers may want to be patient and avoid borderline pitches that may be balls. His results have been less favorable in 2017 as the following chart shows.

His wOBA on pitches put into play is actually slightly higher in 2017 than it has been from 2013-2017. His results are worse than expected on pitches that are less than .5 feet from the middle of the strike zone, but he’s doing surprisingly well against pitches put into play from .5 to 1.35 feet. All in all, his production when putting pitches into play is acceptable.

But unfortunately, he’s swinging at fewer pitches in the top three bins. In the first bin, pitches less than .5 feet away from the center of the strike zone, he’s swinging at only 60% instead of 77%. To some extent, he makes up for this due to the fact that he’s putting 46% of those pitches that he swings at into play, but his performance would likely be better if he swung more at those pitches. In addition, his contract rate isn’t significantly up for the second and third bin, and therefore the percentage of those pitches that he’s putting into play is down.

In fact, he’s swinging at nearly as many pitches in the fourth bin as the second and third bin. Historically, pitches in the fourth bin have been a called ball 79% of the time (81.8% in 2017) compared to 17% of the time in the second bin and 54% of the time in the third bin. Ideally, Chris should rarely swing at pitches that are more than 1.15 feet away from the middle of the strike zone.
Obviously, swinging at more pitches far away from the middle of the strike zone and swinging at fewer pitches close to the middle of the strike zone has had an impact on Davis’s performance. This would suggest that his problem isn’t so much that he needs to swing more or swing less, but rather that he needs to swing smarter.

Going forward, this chart suggests a way for the Orioles training staff to get Chris Davis to improve. It’s reasonably clear to see the distances where Chris Davis has success. It should be easy enough to instruct him in batting practice to only swing at pitches that are a certain distance from the center of the strike zone. Improving his eye should help his performance just as much as ensuring that his swing is working properly.

Chris Davis isn’t the type of batter that should be swinging frequently because he’s unlikely to put pitches into play. Rather, he’s the type of batter that needs to develop a patient eye, so that he gets the opportunity to swing at pitches that he is able to hit. With a batter like Chris Davis, it’s less important to swing frequently than to swing intelligently.

1 comment:

Anonymous said...

Chris davis is going to oblerate Reggie Jackson's career strikeout total, he's already just about to crack the top 100!!!