How Do Pitch Types and Location Impact Blast Metrics?
For this article, we’re going to be taking a quick look at how Blast Motion metrics are impacted by different pitch types and strike zone locations. To do this we’ll be using 750 paired swings between Blast and Cape Cod Trackman data. This includes all swings and not just balls in play. To look at how a swing changes, we’ll be using z scores. This will show how a metric changes relative to a player’s average. We do this that way a player who has outlier metrics doesn’t skew the data. The goal here would be to see how that player changes relative to who he normally is. This article isn’t meant to decide how to value Blast metrics, it just can be used as a tool to provide more context to a swing. This will help coaches know exactly what is happening in the swing when they’re training a player.
Focusing in on three metrics, Bat Speed, Attack Angle and Early Connection, we see a few interesting trends. Bat Speed seems to be lower for breaking balls compared to fastballs. One theory is that hitters on an amateur level swing for a fastball and adjust to a breaking ball so then don’t create the same momentum on breaking balls. Early Connection and Attack Angle are also lower on breaking balls. Early Connection may be lower because a batter’s barrel may go down as the batter’s body begins to move towards the ball. This is a very small sample though, so it’s very possible more data would reveal different trends and allow us to go further in depth, but for now we should just keep this in mind. Also, while the Cape Cod league consists of upper end college hitters, we should remember this study still has amateur hitters on just one team who may be worse at hitting breaking balls, so this may not be a general trend for all hitters at any level. When looking at this data though, we see that context clearly matters in regard to pitch type, and batters do seem to make an adjustment on breaking balls in their swing.
One other piece of context that may be worth considering can be how strike zone location impacts Blast Metrics. Here we’ll look at Bat Speed and Vertical Bat Angle.
On all these graphs, the upper left corner is Up and In to any batter and the bottom right is Down and Away to any batter. The zones vary in the amount of swings from 23 (up and away) to 81 (middle in), so this still isn’t a large sample size and we should be aware of that. With that said, it does seem Bat Speed has a general trend of being faster on swings towards the bottom of the zone.
I found these graphs to be pretty interesting too. There seems to be some noticeable differences in Vertical Bat Angle getting steeper as pitches go down and also away from a batter. This could be because it is hard to hit a ball up in the zone with a steep barrel, while a steeper angle could work lower in the zone. While we are dealing with a really small sample size, this is still pretty interesting to see and something also worth keeping in mind while training players.