High-A Run Environments: The Runaway Cal League

In Minor Leagues, theory by myles9 Comments

Next up in our tour of the minors is Advanced-A ball, alternately known as A+ or High-A. There are three leagues at this level: the California League, the Carolina League, and the Florida State League, and they are wildly divergent environments. The Cubs' affiliate at this level is the Daytona Cubs, who play in the Florida State League. The FSL has the reputation of being extremely pitcher friendly. The Cal League, on the other hand, might as well change its name to the "Hitter-Friendly Cal League," given it's reputation is for offense.

Prospects at this level tend to be a little over a year older than those in A-ball, with the average age typically coming in just shy of 23.

The Run Environment

For information on the methodology, see here.


The first thing to point out is that the Cal League definitely lives up to it's reputation. The run environment there is consistently higher than both of the major leagues. The Florida State League also doesn't dissapoint, producing runs at a lower level than either of the A-ball leagues (though interestingly, it's fairly close to the NL of recent vintage).

The low Class A leagues showed a pretty profound distinction between run environments and power. At high-A, the trend is quite a bit more divergent. 


The FSL is actually even less conducive to homers than the MWL, despite being home to more advanced hitters. In Myles's excellent profile of Dan Vogelbach, he noted that Daytona's home park is relatively homer-friendly. This is true, but given the low starting point of the league as a whole, we should expect prospects there to have lower power outputs.

Cal League games feature as many homers as the big leagues, both on a per-game (data not shown) and per-contact basis. This is pretty profound, since the typical Cal-League hitter is about six years younger than his counterpart in the majors. The sharp distinction between California and Florida also makes clear the difficulty in comparing players across leagues at these levels. A few months ago I wrote a piece looking for comparables for Javier Baez, and noted that Brandon Wood matched up fairly well. This data should help to make clear why Baez's career to that point, which was spent mostly in the Midwest and Florida State Leagues, was more impressive than Wood's breakout in the Cal League in 2005. That's not to say the comparison is entirely without merit, but the contexts are extremely different.

Others could probably better speak to trends in the Cal League, but I wonder whether teams are increasingly letting their good arms skip the league altogether. It seems to be moving away from any relevance whatsoever to major league environments.

A vs. Advanced-A

I came across an interesting article a few months ago over at The Hardball Times that compared the level of play at various minor league levels. It had this to say about the differences between A-Ball and A+:

Back in my college coaching days, I worked for a head coach who had been drafted and played a few years in the minors before returning to coaching. He once told me that he had more success in the more advanced levels than he did early on. The reason was that, in the lower minors, he faced pitchers with electric arms with no control or off-speed pitches to speak of, but who could reach the upper-90s or triple-digits. As he advanced, the pitchers were better and had a better plan, but he wasn't blown away as often with ridiculous fastballs. His career ended likely because he lacked the bat speed to hit pitchers who can do both (major league pitchers), but his theory is valid. 

Arms slow down over time. Arms in the low-minors are younger. Therefore, arms in the low minors have the ability to throw harder. Those pitchers can't usually do much else yet, but they can throw hard.

Unfortunately my dataset has nothing to say about pitcher velocity or pitch usage at the two levels. On ther other hand, we might be able to tease out changes in control. I took a look at some three-year averages to find out. 

2011-2013 Three Year Averages
  League BB%
A Midwest 8.7
  South Atlantic 8.7
A+ California 8.8
  Carolina 8.6
  Florida State 8.4

Walk rates don't seem to be all that different between A and A+, though that could be because both pitchers and hitters work the strike zone at an increased level. (Spoiler: walk rates don't change much at AA or AAA, either. Rates do seem to be significantly lower in the majors). Next I took a look at hit-by-pitch data. The theory here is that while hitters and pitchers are selected for patience and command, respectively, hitters will be selected to a much lesser degree for their ability to be hit.

2011-2013 Three Year Averages
  League HBP%
A Midwest 1.26
  South Atlantic 1.40
A+ California 1.29
  Carolina 1.38
  Florida State 1.26
AA Eastern 1.17
  Southern 1.17
  Texas 1.23

In fact, we don't see much of a decline in HBP until AA. (Of note to those of us who have lamented Baez's lack of HBP's in the Southern League). This is one indicator that pitchers don't really start getting weeded out for poor control until they reach the high minors.

In my A-ball article, I noted in passing that defenses seemed particularly poor at that level. At high-A, there seems to be some improvement. I calculated unearned runs as a percentage of total runs for each league over the past three seasons.

2011-2013 Three Year Averages
  League UER%
A Midwest 16.7
  South Atlantic 15.3
A+ California 13.3
  Carolina 14.5
  Florida State 14.0

I'll have more to say about trends in defense and control throughout the minors in future articles, so I'll leave it at that for the moment.


The oft-repeated refrains about the A+ leagues seem to be on-target. The Cal League is a hitter's paradise, and the FSL is a haven for pitchers. The Carolina League has been given the short shrift here, but it plays more neutrally.  

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  1. Omar Little

    uncle dave wrote:

    @ Omar Little:
    Do you think the anthropologist Margaret Mead’s strange behavior of late can be explained by a private marijuana addiction?

    Good question.

      Quote  Reply


  2. Omar Little

    If anyone tells you Clowney had a bad (or even subpar for him) game, you spit in their face and say, “Your rong!”

    I’ll tell you what, though, Ole Miss DE Robert Nkemdiche looks legit. Raw as hell, but he looks like Reggie White light…Reggie Lite.

      Quote  Reply


  3. dmick89

    Nice article again, GW. Could the worse control be seen in increased wild pitches? I’ve always assumed that pitchers had worse control in the low minors, but you see to show that’s not true.

      Quote  Reply


  4. rattier

    Well done on this series GW. This is cool stuff, and info that I’ve not seen elsewhere, except for the ever-present but always vague, “oh yeah, that’s a pitcher’s league”.

      Quote  Reply


  5. GW

    thanks, guys.

    @ dmick89:

    yeah, it could be. i toyed around with using (wp+pb)/g, but ended up going with hbp instead, since I don’t have to control for baserunners. (since a wild pitch with no one on is just a ball). maybe i’ll add it in the next post.

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