This is for now the final article of my launch angle series (Sorry Carson, or whoever edits all those articles).
Alan Nathan wrote an article that suggested that a steeper attack angle (upward swing angle of the bat) produces more extra-base hits but has a cost in power.
That makes sense since the average pitch only has a downward angle of like 5-10 degrees and if you swing up at 20 degrees you are on plane with the pitch for a shorter time.
Unfortunately, we don’t have attack angles for pro players in games, because there are cheap bat sensors that measure that now but they have only been used in ST and futures games (suggesting attack angles of like 8-15 in most cases I have seen), but I will assume that the average exit angle over a long sample should be pretty similar to the attack angle, or at least correlate closely.
For that, like in my last post, I looked at guys that had at least 500 ABs in 2015-2016.
I looked at LAs of <7, 7-9, 9-11, 11-13, 13-15, 15-17 and >17 degrees.
I did not really find very big differences. Below 9 degrees it was about 2 percent lower than at the higher angles, but after that there isn’t a big change. Even looking at the small sample above 19 degrees, it was only elevated to 21.6%, which is higher but not spectacular (and it was a small sample of only seven batters).
To look further I looked at exit velo. If I looked at the batters above 91 mph they averaged 23% Ks, vs 19.1% for the below-91 group.
So there may be some penalty for swinging hard, but there also might be a selection bias, since low-power swing-and-miss guys are weeded out while power hitters with bad contact skills produce more and stay in the league longer.
Overall, looking at those data, I would say that contact is mostly a skill that is separate from launch angle. In my prior articles I have shown that there is a punishment for angles that are too high, but it seems to come more in the form of pop-ups and routine fly outs and thus lower BABIP, and not in the form of whiffs. Now we know there are some high-LA, high-whiff guys like Chris Davis for example, and those guys do trade BABIP for ISO with higher LAs to get the most out of their contact, but the more extreme uppercut likely isn’t the source of their whiffs but an attempt to compensate for them by trying to strengthen their strength while “punting” their weakness.