On Tuesday, I unveiled the latest version of my xHR/FB rate, and introduced a new metric that replaced the Brls/BBE equation component. Technically it’s new, but it’s not unfamiliar, as I simply swapped out the BBE denominator for true fly balls, which is just the fly ball total found here, minus pop-ups (IFFB). Yesterday, I dove deeper into the new Brls/TFB metric, sharing some data on my player population and then listing and discussing some names affected by the switch. Today I will continue on that Brls/TFB course with more fun stuff.

First, we’ll begin with a table packed with correlations:

Brls/TFB & Brls/BBE Correlations YoY Correlation Correlation with HR/TFB Correlation with HR/FB Brls/TFB 0.759 0.851 0.859 Brls/BBE 0.764 0.833 0.839

Both barrels rates correlate rather strongly from year to year, which is a major positive. It’s interesting to find that Brls/TFB is ever so slightly less stable, which commenter Konoldo from yesterday’s post called. It’s so close that they are essentially identical, but my thoughts are that the larger Brls/TFB values widen the range from minimum to maximum, and a wider range means more room for year-to-year variation. Perhaps it’s silly to try to justify the slightly lesser correlation, as it’s just two seasons in the calculation. After 2018, Brls/TFB may very well pull ahead!

The next two columns are the more important ones. We can see here that Brls/BBE was indeed a fantastic proxy for HR/FB, which is why it was the star of my original Statcast-fueled xHR/FB rate. But, Brls/TFB correlates even better with HR/TFB and HR/FB! When you really think about it, that’s a pretty amazing correlation, as the barrel metric is the straight combination of two skills (exit velocity and launch angle), with no results mixed in. A fully skill-based metric explains about 86% of the variation in HR/FB, awesome. It means we could essentially just look at that one metric and be done, and have a perfectly satisfactory way to evaluate home run power from a skills perspective. But who wants to settle for satisfactory?! Not I!

Now let’s check out the top 20 Brls/TFB leaderboard:

It’s just mind-boggling how much better than the field Aaron Judge was in the barrels department, no matter which denominator you choose to use for your Brls ratio. Is it humanly possible to be that good again? While his barrels rates fully support his bonkers power, it’s, like, really hard to maintain such an elite level.

How do you like those fourth and fifth ranked names?! Erik Gonzalez I mentioned yesterday, so, Drew Robinson?! He made his MLB debut this season for the Rangers at the age of 25, struck out a ton, hit for lots of home run power, and (pun not intended, but this totally works) drew his fair share of walks. The HR/FB rate (26.1%) was far above what he had done in the minors, so it’s obviously questionable whether a repeat is in the cards. But he certainly deserved every bit of that HR/FB rate given his penchant for barreling his flies.

Man, talk about a Ryan Zimmerman renaissance. He nearly doubled his 2016 Brls/TFB rate. Was it just all about health with him? Given his age and health history, he’s a prime bust candidate. Oh, and the fact that he just posted a career high ISO…at age 32. Even when he was in peak form in his mid-20s, he never reached these heights.

Someone please tell Howie Kendrick that fly balls aren’t the devil. Maybe he could talk to Christian Yelich about how to raise his FB% above 22%, a level he hasn’t reached since 2011.

Lane Adams?! He’s the third complete surprise in this group of 20. Adams actually made his MLB debut back in 2014 with the Royals, recording just three plate appearances, before joining three different organizations, wallowing in the minors, and returning with a bang as an Atlanta Brave(s?). Small sample size like the other two surprise names, and he also struck out often with an inflated SwStk% mark. But hey, it’s likely Ronald Acuna doesn’t open the season as a member of the Braves starting outfield, and he’s no lock to be called up shortly if his Triple-A performance doesn’t warrant it. So Adams may actually earn some plate appearances until the Acuna show begins. Maybe some cheap power for your NL-Only team?