One school of thinking about the MLB trade deadline, which passes at 4 p.m. Eastern time, is that teams should address their weaknesses and become more balanced in preparation for the stretch run. The notion, which we’ve taken as a given around these parts in the past, is that sacrificing in some area of strength (whether on offense, pitching or defense) to plug a weakness makes a team less vulnerable in the postseason. But is that true? Certainly teams should patch up their weaknesses if it doesn’t mean taking away from their strengths, but all else being equal, balance for its own sake may not necessarily help improve a team’s chances.
It’s easy to look at a team’s offense/defense balance — defined as how closely matched a team’s run-scoring and run-prevention capabilities are. We can quantify the clubs most in need of it at the deadline this season by indexing each team’s (park-adjusted) runs scored and allowed per game against the league average. In the chart below, the teams in the bottom right-hand corner are the most balanced — they’re good at both scoring and preventing runs17 — but those in the adjacent quadrants have a weakness in one of the two categories. (Those in the top left are just bad at everything.)
But to examine the broader question of whether balance helps a team, we need to see if our measure of balance — specifically, the absolute difference between a team’s index and the league average of 100 on both offense and defense — tracks meaningfully with a team’s future success after controlling for its overall talent level.
To that end, I computed the same offensive and defensive indices as above for each team on July 31 of every season since 1986, when the trade deadline was permanently moved to that date (except this year, when the commish moved it to Aug. 1 because July 31 fell on a Sunday). As a first pass, I checked whether a change in a team’s balance correlated with improved play over the remainder of the regular season — and the relationship was practically non-existent.18 I then did the same thing but for eventual playoff teams only … and got the same result.19 Finally, I looked at whether a playoff-bound team’s balance had any real bearing on its World Series odds after controlling for its talent, and again, a team’s balance had no significant effect. (If anything, less balanced playoff teams have tended to win the World Series more often since 1986, though that finding is likely just noise.)
In other words, balance isn’t something for a team to seek at the deadline — talent is. Teams should be wary about dealing from a strength to improve a weakness if it doesn’t leave them in a better overall place than where they started. Even under the bright lights, a run saved is still worth the same as a run scored, balance be damned.
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