On this past Thursday’s edition of Baseball Tonight, Jonah Keri was called upon to discuss MLB team run differentials (he also wrote about it here). He pointed out that this early in the season, run differential may be even more powerful in predicting end-of-season win-loss records than current win-loss records themselves. This is not the first time I’ve heard this tidbit, and Sean Forman does a nice job of explaining the rationale in this piece. In sum, run-differential says more about the quality of team than does win-loss record because, especially early on in the season, win-loss record can be skewed based on chance. Hence, a team’s 162-game win-loss record is best explained by a combination of runs scored, runs allowed, and luck.

Keri pointed out that this is about the time of the season when we can start trusting run differential to tell us about the quality of a team. Russell A. Carleton illustrates why this is so here, though his more advanced calculation, which employs Cronbach’s alpha, seems to suggest we should wait a few more weeks.

Nevertheless, this topic got me thinking about which MLB teams are most balanced (a lot of runs scored and few runs allowed, or, in other words, solid hitting, pitching and fielding).

First, I looked into team OPS numbers:

Quick Comments:

  • As is to be expected, the Rockies, who play well-above sea level in Denver, CO, have the highest OPS (though I would argue that the number is still impressive even after accounting for geography). I did not adjust for park factors in this particular analysis.
  • The Angels, Tigers, and (especially) the A’s all have impressive places within the plot (a team that has a better OPS than that which it surrenders to opponents is of course below the 45-degree line).

I then plotted runs/game vs. runs allowed/game and calculated a standardized version of run-differential: $\frac{\text{runs scored} - \text{runs allowed}}{\text{games played}}$. Drawing

 

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 Quick Comments:

  • Again, the Oakland A’s post a very, very impressive run differential figure.
  • The 17-28 Cubs post a record not at all reflective of their run-differential.
  • The D’backs could use some pitching help.
  • Though Colorado scores the most runs in baseball (see discussion above), they are still holding opponents to much fewer runs than they score. Thus, seeing that they play their games in the same ballpark as their opponent, this analysis bodes very well for the Rockies.

With all of this in mind, the most impressive teams thus far in terms of balance (which is vital to sustained success in any sport) and the ones that would seem to be in it for the long haul are:

  1. Oakland
  2. Detroit
  3. San Francisco
  4. LA Angels
  5. Colorado Rockies

You can of course interpret the data however you’d like. These are my five most balanced teams, as of now.  Oakland’s season is off to an unbelievable start and they deserve particular recognition (at least double the per game run differential of that for every other team!) but, of course, who knows what the future holds. This list is very likely to change as the season progresses, but, for now, realize that the A’s are playing tremendous (dare I say historic?) baseball.