The Triple-Slash Line Conundrum by Era

Just a few weeks in the past, I regressed as a author. I regressed lots, truly: twenty years price of slash line information regressed towards twenty years of run scoring information in varied methods. However — and it is a harmful sentence, and often a nasty one — somebody requested me a query on Twitter and I wish to reply it. Specifically: was batting common all the time the weakest correlation to run scoring among the many slash line statistics, or has it solely change into so just lately?

That is going to be a fast hitter. I broke the sport down considerably arbitrarily, utilizing eras outlined by OOTP Good Workforce. I began in 1947 and went up till 2000 (the outcomes of the 2000s had been in my earlier article). Right here’s what these 2000s outcomes appear like, which ought to each provide you with an concept of the correlations immediately and preview the format for the remainder of the article:

With out additional ado, let’s get began.

Golden Years, 1947–1960Now, these weren’t the golden years for me, as a result of I wasn’t alive, however I assume that’s what some folks name this period of baseball. Jackie Robinson! Ted Williams! Stan Musial! Willie Mays! Batting common mattered extra, but it surely nonetheless didn’t matter:

What do I imply by that? Effectively, for those who predict run scoring with OBP and SLG, you get a 0.908 adjusted r-squared to precise runs scored. Predict run scoring with the complete triple slash line, and also you get an adjusted r-squred of 0.91. Batting common did higher, by itself, as a run scoring predictor, however utilizing OBP and SLG was the gold normal within the golden years.

Baseball Increase, 1961–1979This is a broad period that folds in some pitching-dominant years that led to guidelines adjustments, the early a part of the pace period, and a few early-60s dwelling run mania. It’s additionally an period the place, if you understand OBP and SLG, you don’t have to know batting common to foretell run scoring:

Just like the 1947–60 span, utilizing OBP and SLG as predictors does simply in addition to utilizing all three statistics. Extra particularly, OBP/SLG had a 0.922 adjusted r-squared to runs scored. The total AVG/OBP/SLG regression checks in at 0.923. Common… for those who’re already 99.89% of the there, it’ll get you that final tiny little bit of explanatory energy. That’s not precisely a ringing endorsement.

Defensive Period, 1980–1992Even although I wasn’t alive for an enormous chunk of this period and wasn’t following baseball for the overwhelming majority of it, it’s one in all my favourite eras, because of Ozzie Smith, my single favourite baseball participant and, per my mother, the particular person I’ve most emulated in my life. I spent numerous hours mimicking the defensive performs I noticed on my “Ozzie, That’s a Winner” VHS tape, which my uncle had recorded on native entry TV in St. Louis. I’m a lefty, so I used to be doing them backwards they usually by no means led to me turning into a defensive wunderkind, however none of that mattered to me; I simply wished to be like Ozzie. Uh, the place had been we? Oh, proper. Common didn’t matter:

Utilizing the factors from above, OBP/SLG checks in at 0.863, and an all-three-slash-stats regression checks in at 0.864. It’s attention-grabbing to notice that OBP and SLG clarify the bottom proportion of variation in run scoring on this period, which I attribute to the massive vary in crew baserunning technique and effectiveness, however that’s not the purpose of this research. The purpose is that for those who already know a crew’s OBP and SLG, you don’t have to know their batting common to foretell what number of runs they scored.

The Energy Years, 1993–2000I reduce this one off at 2000, since my earlier article already coated the twenty first century, however OOTP extends it to 2004. Regardless, you guessed it:

This time, the adjusted r-squared is similar whether or not you take a look at OBP/SLG or AVG/OBP/SLG. So there you’ve it: all through the eras, the correlations have remained the identical. In case you’re attempting to foretell a crew’s run scoring and have already got their on-base proportion and slugging proportion, you possibly can cease there. Batting common gained’t add something to the equation.