Atlanta Braves 2014 Preview: Aging Trajectories

Atlanta Braves Home Run Leaders

The home run rate (home runs divided by at bats) of the top 12 home run hitters in Braves history.

Being a consumer of sabermetric analysis, a member of a fantasy baseball keeper league, and a die hard Braves fan, the age of players is extremely important. You want youth with enough production that it makes sense to take the 23-year-old over the 30-year-old veteran.

When the Braves signed five of their young stars this off season to long-term deals, the team got their best players at below-market value for their most productive years, the mid-20s. They didn’t attempt to re-sign free agent Brian McCann, probably the second best offensive catcher the last five years (and the captain of the Baseball Police), who is 30. These moves show their fans and baseball that the front office actually knows what they’re doing and recognizes that you can’t build a team through free agency anymore. It’s too expensive, and it’s too risky. (Unless you’re the Dodgers, for whom expense and risk don’t apply.)

This trend toward youth isn’t relevatory, of course, but it is being statistically proven over and over again. A recent FanGraphs analysis by Jeff Zimmerman demonstrates how hitters’ production has changed during different eras of the game. Most noticeably, since the end of the steroid era (2005), hitters don’t improve once they hit the majors. Production declines from year-to-year as a player ages. (Zimmerman uses wonky statistics, weighted on-base average and weighted runs created, to show this.) This decline is due to three reasons:

        1. The ban of PEDs between the 2005 and 2006 season
        2. Better defensive scouting by major league teams
        3. Better minor league training, so players are ready once they reach the majors

It’s not that Freddie Freeman of the Braves won’t get better, it’s that – nope, on average, Freddie Freeman has already peaked using OBA and runs created. But who else is coming down the prospect pipeline in the Braves’ minor league system or free agency that can match his production at that price? No one right now, hence the multi-year contract at 23. (Obviously there are other ways to value a player; and I’m not 100% sure that Zimmerman’s trend will hold for Freeman, Heyward, or any other player for that matter.)

R Graphs: Home Run Trajectory

Combining my foray into R with baseball is a neat graphic based on a recent post from the authors of Analyzing Baseball With R.  They use the R statistical programming language to go through the copious amount of baseball data and spit out interesting graphs. They also have an accompanying blog, where they post the code they use for their various projects. So nice of them!

I used their generosity to alter their home run trajectory comparisons. In the original post, Jim Albert compared Ryan Howard’s home run rate (a simple Home Runs / At Bats computation) by age with players similar to Ryan Howard. I switched the original players in the post (a graphic based on a Phillies player is gross, despite Howard being washed up with a laughable contract, and demands to be changed) with the top 12 home run hitters in Braves history. This is shown in the graph at the top. The home run rate, even for great power hitters, drops when a player gets to about 30. (Hank Aaron plays by different rules.) I’m turning 30 in a couple of months. It’s only downhill from here.

With a helpful hint from the author, I attempted to find the home run rate of these Braves while they only played for the Braves instead of over their entire career. My coding prowess is limited, however, so I couldn’t figure out how to do that. (Once I do, I’ll post.) Aaron, Chipper Jones, and Brian McCann (at least through 2013) played for the franchise for their entire careers, but some of the others guy didn’t.

(Side note: I don’t really understand how GitHub works yet, but I hope to start dropping my code and data there in the near future.)

Braves Prediction

With Atlanta’s pitching in shambles and a good offense, I predict a 2nd place NL East finish, a battle for the 5th wild card spot, and losing in the wild card game to the Giants.


About Jay

Health Policy Wonk. Slow long distance runner. Returned Peace Corps Volunteer, Cameroon '06-'08. Former Night owl.
This entry was posted in Current Events and tagged , , , , , , , , . Bookmark the permalink.

One Response to Atlanta Braves 2014 Preview: Aging Trajectories

  1. Bob Hubbard says:

    Reblogged this on Lean Learning and commented:
    While this post does not fall into what I would traditionally call ‘lean’ thinking, it does point out great ways to use statistics to interpret the world. Plus, Jay went to UGA for grad school… and as a former Bulldog myself, I felt duty bound to “Like” and “Reblog” this great post about the baseball team I’ve been following since 1966.

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