Long time reader, but newly-registered to the forums. I wanted to post about a perspective that I've been exploring recently: batting efficiency. As the name suggests, batting efficiency (at least the way I see it), measures what the batter accomplished given his opportunities. Stated more simply, it looks at what he did with what he had to work with. I am not sure if this of interest to anyone, but in case it is, here's a basic overview.
*Like slugging, a batter's "efficiency" measures how many bases he advanced over the total number of possible advancement opportunities. A single is 1/4, a double is 2/4, and so forth. While slugging percentage is undoubtedly a valuable stat, its shortcoming (in my view) is that it doesn't really say much--except by way of comparison. Sure, we know that a .600 slugging percentage is great, but what does it really say? -That a batter averages a hair over a single base advancement per at-bat.
*Batting Efficiency goes a step further than slugging. It takes into account the total number of possible advancements (including base runners, as situated), as well as the batter's. For example, with a runner on first, there are 7 total base advancements that can be made. If the batter strikes out: 0/7. A single that advances the runner to second: 2/7. A single that advances the runner to third: 3/7. Sac fly: 1/7.
*Batting Efficiency is progressively weighted, in that it reflects the notion that the closer a runner is stationed to home --1B
*In a similar vein, the more runners on base, the more opportunities for the batter to succeed/fail in converting advancements. In the bases loaded scenario, the batter has 10 possible base advancement opportunities. A strikeout means he went 0 for 10. A single that advances all runners one base--4/10 (.400). A bases clearing double--8/10 (.800). A sac fly that scores the runner from third--1/10 (.100), etc.
*With this backdrop, I set out to measure Miguel Cabrera's "batting efficiency" and compare it to Mike Trout's. A couple interesting things to keep in mind is the fact that Mike Trout is--by far--the faster of the two, which would seemingly give him an advantage in batting efficiency by his ability to stretch singles into doubles, doubles into triples, and so forth. Also, Mike Trout generally batted second in the line-up this year (and also batted lead-off). As shown below, though, the order in which Trout batted in the lineup did not really affect the number of base advancement opportunities he had (at least in comparison to Cabrera, who batted third). Finally, not only is Trout a fast runner himself, he usually batted behind fast runners--Aybar and Bourjos--which would presumably give him an advantage in batting efficiency. The surprising thing is that it didn't.
Here's the breakdown of Trout vs Cabrera in batting efficiency during 2013:
April-- 100 base advancements / 628 opportunities (.159)
May -- 121 base advancements / 627 opportunities (.192)
June-- 121 base advancements / 625 opportunities (.200)
July -- 96 base advancements / 503 opportunities (.190)
August-- 117 base advancements / 565 opportunities (.207)
September--108 base advancements / 597 opportunities (.180)
Total base advancements 663 / 3,545 opportunities (.187)
April-- 142 base advancements / 643 opportunities (.220)
May-- 168 base advancements / 680 opportunities (.247)
June-- 204 base advancements / 601 opportunities (.339)
July-- 81 base advancements / 386 opportunities (.209)
August-- 143 base advancements / 574 opportunities (.249)
September-- 65 base advancements / 435 opportunities (.149)
Total base advancements 803 / 3,391 opportunities (.236)
As noted, Trout actually had slightly more advancement opportunities (+154) than Cabrera, yet he converted 140 fewer bases (663 vs 803). More impressively--and definitively--Cabrera converted bases as a much higher clip--23.6% vs 18.7%. Without question, Cabrera was the more efficient of the two and, when combined with his individual tallies, shows him to be the superior offensive player (relative to Trout), by a long shot.
In case anyone is interested, 'batting efficiency' (according to my terms), accounts for intentional walks and hit-by-pitches as 1/1 (regardless of number of runners or their respective base stations). Batters are not credited for advancements gained through errors.
I'm not under the delusion that 'batting efficiency' (or 'advancement average,' or whatever you want to call it) is a brand-new concept. That said, I don't often hear a batter's production measured in terms of his efficiency and, for that reason, I though it lends interesting perspective. I'd be glad to hear what others think and would be happy to share a more detailed breakdown of my numbers.
Edited to correct a formatting error.