Exit Velocity, Launch Angle, Spin Rate. With the addition of Statcast to MLB parks, many additionally terms and statistics are quickly becoming part of the lexicon of baseball speak. Even for a baseball fan with some familiarity with advanced metrics, it can be difficult to decipher what these terms mean, or how this information is useful. The most common way this appears to be taking shape is through what is being dubbed as the “fly ball revolution”. Maybe you’ve heard of it? If you have, you are most likely reading some form of research that has its basis in some of these new Statcast metrics.
Today, I want to touch on some hitting metrics and how they relate to Adam Frazier. But first, let’s give a little bit of background into some of these terms. In general, the concept of batted ball types (until recently) has circled around ground balls, line drives, and fly balls. The metric IFFB% would be provided as well in many instances, but it is/was a subset of total fly balls. These categorizations came out of the data that was provided at the time (Retrosheet, BIS data, etc.). However, because of Statcast we can alter our metrics slightly to allow for different insights. First, instead of 3 batted ball classification historically used, we need to acknowledge that there are actually 6. Luckily, Andrew Perpetua has done a lot of work on this topic and has pieced together some useful information on this topic at his site.
|DRIBBLE BALL – Balls hit below zero degree launch angle|
|GROUND BALL – Balls hit with launch angle between 0 and 10 degrees|
|LOW DRIVE – Balls hit with launch angle between 10 and 19 degrees|
|HIGH DRIVE – Balls hit with launch angle between 19 and 26 degrees|
|FLY BALL – Balls hit with launch angle between 26 and 39 degrees|
|POP UP – Balls hit with launch angle over 39 degrees|
(All of this information comes from xStats.org and is linked above.)
Let’s hash through some of this. If you wanted to use the old classifications, you would say that a ground ball is under 10 degrees, a line drive is between 10 and 26, and a fly ball is over 26. Intuitively, we understand that there are two types of ground balls and two types of pop ups. We may never think of each of the two classifications like this, but let’s reason through it. If you wanted to talk about the worst type of batted ball, that would be a pop-up. You hit one directly up in the air, and you don’t get good results on these the majority of the time (.055 wOBA). Yes, they can go for a home run. However, the BABIP on these balls in play is only .033, and they only fall for a hit around 4% of the time. Pop ups are bad. We understand this. However, pop-ups are still “fly balls” under the old definition of batted balls. Your newly defined fly balls from the above table are not pop-ups. These are much more valuable, mostly due to the high quantity of HR they produce. This also makes sense. You hit the ball in the air but don’t pop up, and you are more likely to get a home run out of it. If you don’t hit a home run, it is easier for a fielder to get under it than for a line drive (explaining the low BABIP).
A similar story with ground balls. If you hit the ball directly into the dirt, the contact with the ground will likely slow the ball down to the point that a fielder can make the out. About 19% of the time you’ll get a hit (hey, it’s better than pop-ups) but if you get a hit you are most likely just getting a single (92% of the time). That’s fine. Singles have value.
We know that ground balls have a higher BABIP than fly balls. However, balls hit below zero degrees possess a BABIP far less than standard ground balls at .194. Brass tacks, hit a ball directly into the dirt and you might get a single. You most likely will just get out.
The two line drive categories could be explored in more detail, but to keep it simple: Line drives are good. We already know this. For brevity’s sake, I’ll touch on this in future posts.
Phew… that’s a lot of information. But you’re a Pirates fan (or at least I am assuming you have some interest in the Pirates). So to tie this to the them, I want to talk about Adam Frazier.
Kevin talked about Adam Frazier a few weeks back. At the time, his 136 wRC+ and .355 babip were bound for regression, but the question was “how much?” Since then his offensive production has been 45% below league average. The last month has not been kind to Frazier.
But again, this isn’t surprising, someone will play well, then they won’t. You can go 4-4 then 0-4 with relatively little difference in batted balls between games. So, using our newly defined batted ball categories, let’s look at Frazier’s profile to see how he measures up.
The first thing that stands out is that Frazier limits pop ups. This has always been a part of his game. While not entirely apples to apples, we can look at the entirety of his career and see that since being drafted out of Mississippi State in 2013, he has only hit infield flies on 5% or more of his fly balls one time (6.7% in AAA during 2016). This is helpful. From above, our batted ball charts above, we know that the least valuable type of batted ball are pop ups hit over 39 degrees (.055 wOBA) and Frazier limits these. His profile, as a whole, is slanted toward ground balls – above league average in both types, and because of this, will be very BABIP dependent.
The downside to this is that he does not hit the ball hard consistently. His average exit velocity is just over 84 mph, below the league average. On fly balls specifically, his average exit velocity is even lower. Because of this, it probably would not be worthwhile for him to hit more fly balls than he has previously, if a specific shift wasn’t also increasing the force with which he hits the ball. However, if he could ever so slightly alter his swing, to minimize the weakly hit ground balls, the bat could be special. Is that possible? I don’t know. The change would likely be very minor, and maybe zero change is needed given variance in batted ball types. That said, he’s a great example of the type of player benefiting from not hitting as many fly balls. Currently his exit velocity just wouldn’t sustain it.
Based on his quality of contact, his Expected on Base Average is .336. That’s a very useful, but non-star, big league player, but probably not the type of player who ever posts the type of stats that are rewarded most in arbitration (HR and RBIs).