Durham Bulls Hitting (and Pitching?) at Game 36

I've become fascinated with a statistic called "Secondary Average" this year and have started tracking it for individual Durham Bulls and for the team. Batting average is pretty simple. The player hits a fair ball and gets on base. But it leaves out a lot of other stuff. Others stats that are out there such as On Base Percentage and Slugging Percentage make up for that, but, for me, the numbers don't connect all that well.

I'm not alone. What got me started on secondary average was a Victor Mather article last April in the New York Times. It's pretty simple. Count up the total bases, back out the singles, add in the stolen bases, back out the caught stealing and divide by the at-bats. Then compare the batting average to the "secondary average".

Let's take a look at the Bulls as a team. This chart shows team  averages on the season. Just the last 15 games are shown. As of today, the Bulls batting average is .269, a few points over the International League average (and ranking 6th in the league). The Bulls secondary average is .307, indicating plenty of extra-base hits, walks, and stolen bases. They are essentially in the middle of the pack on all measures.

An interesting puzzle for all the league is the proliferation of home runs (Gwinnett has hit 59 in over their 37 games!). My guess is that using major league baseballs has a lot to do with it.

This table takes a look at Durham hitters and is sorted by batting average. I was surprised by Kean Wong's numbers and they may be an indication why he has not gained the attention of the Rays after all this successful time with the Bulls. If you want to worry, then worry about the Bulls' catchers. But, wait for the next chart to think about that.

Name	G	AB	BA	2A	Diff
Kean Wong	30	111	.369	.306	-.063
Jake Cronenworth	33	122	.361	.344	-.017
Mike Brosseau	33	122	.311	.352	.041
Andrew Velazquez*	23	93	.290	.269	-.021
Nick Solak	33	108	.269	.296	.027
Nate Lowe*	24	82	.268	.451	.183
Emilio Bonifacio	15	49	.265	.204	-.061
Christian Arroyo*	21	72	.250	.347	.097
Jason Coats	23	79	.228	.278	.050
Jake Smolinski	29	108	.222	.296	.074
Mac James	16	48	.208	.188	-.021
Nathan Lukes	25	75	.200	.280	.080
Nick Ciuffo*	22	79	.152	.139	-.013
Team	36	1172	.269	.299	.030
* On 40-man

I got to wondering if this stat could tell us something about Bulls pitching. Measured by ERA the Bulls have certainly not had stellar pitching this year, but as a team, they are at the league average.

However, if you start plotting the Opponent's batting average and secondary average, something pretty interesting jumps out. The opponent's secondary averages are well below their batting averages. What does that mean? It means that they are not getting very many extra-base hits, walks, stolen bases (and often getting caught stealing when they try). That fits with what we know about Rays' pitching philosophy — avoid walks, let the fielders do their jobs (and maybe all that shifting?).