Like about 80% of everything that’s ever been written by anyone on the internet, this started out with me just messing around with a little bit of curiosity. I noticed that Nick Castellanos and Alex Avila both hit a pretty small number of popups in 2014, which struck me as a touch odd given their own specific offensive struggles. There’s no single way to evaluate a player, but no popups = good and popups = bad is a fairly good rule.
So that got me wondering about the frequency of the entire team. So I looked at the players on the team who saw 600 or more pitches in 2014 and calculated their Swings Per Popup or SW/PU. I would have done PU/SW, but the numbers get small and the laws of math say it’s okay.
The bottom of this chart won’t surprise anyone, but I think the top two people might. Avila has a good eye, but people generally weren’t happy with his swings last year. Castellanos struggled quite a bit, as well, although a lot of that was contact issues rather than issues when contact was made.
So hey, that’s all well and good. A couple guys did a nice job avoiding popups! But then I started to realize that there’s an obvious flaw in this method. If you swing at everything and miss a lot, you drive up the swing count. So then I added in swinging strikes, or whiffs. I called the new number SW/WHUP (pronounced ‘swup’), or swings per popups plus whiffs. Now let’s see!
This gets interesting in a lot of ways. Martinez is obviously not a human person, but Kinsler rockets up the list thanks to his lack of swinging strikes. He might pop up a lot, but he doesn’t miss. Both are pretty useless, who cares which he does (obviously a popup is at least a bit worse). Avila and Castellanos return to their place at the bottom of the list, and while this still doesn’t capture offense perfectly, it feels a little better. This is essentially the number of swings that have no chance of becoming a hit.
Call them Worthless Swings. Now of course, there are plenty of ground balls and fly balls that are worthless too. But those aren’t measurable with the available data to the same degree of precision. We know that Avila takes, at most, three swings between each worthless swing and Martinez takes at most about 10. There might be others mixed in, but this is a good ceiling. Maybe StatCast will help parse it down further.
Just to give you an idea of where the Tigers sit in relation to league average, here are numbers for 2014.
The Tigers take fewer worthless swings than other teams. There’s a lot more fine tuning to be done to see if this is a useful tool, but I think I like it at first glance. The Tigers avoided popups and whiffs nicely last year, now all we need to know is if they’ll do it again and if it tells us anything! (FWIW: This seems like a metric that should be predictive of itself in the future)