One of those outputs, in the batter comparison module, is time slices that span multiple seasons. You can see more specific time ranges--such as the ones we published several years back that looked at what the difference in peak performance looks like when we compare full season numbers with two-month snapshots.
The time slice that has always interested us is the one we call "back to front"--a look at July 1st of one season through June 30th of the next season. It began as a lark just to see what these numbers looked like, but it became clear that a different type of dynamic seems to be in existence when we compile these numbers and put them alongside the standard "front to back" seasons. As you'll see in a minute when we display both "front to back" and "back to front" data for peak performance in the past decade (2010-19), there's a difference in the quantity of those peaks: it appears that there are systemically about 30-35% fewer of them when we slice "back to front."
Why this is the case might be worth some amount of speculation, but we will hold off on that until the point in time when David extends his Day-by-Day database further back in time. (For various reasons, he's not taken Retrosheet data now available prior to 1957 and incorporated it: we can hope that he'll do so at some point in the not-too-distant future.)
So--here are the 27 "front to back" peak seasons from 2010-19, defined as a season in which a hitter qualifying for the batting title produced an on-base-plus-slugging (OPS) of 1.000 or higher:
These are listed in descending order of OPS. The list might make it clear to Bill James why a number of people consider Bryce Harper to be a superstar, despite his erratic performance level over the years. (Not shown on this list is a non-qualifying year--2017--where Harper also produced a 1.000+ OPS.)
There are no mystery guests here, though certain players who were dominant early in the decade (Jose Bautista, Chris Davis, Albert Pujols, Miguel Cabrera) have all faded, aged, and/or retired in the intervening years. The breakout of these peak seasons by year is as follows--2010: 4; 2011: 2; 2012: 0; 2013: 2; 2014: 0; 2015: 3; 2016: 1; 2017: 5; 2018: 4; 2019: 6.
Are you surprised by the fact that Mike Trout is only on this list twice? His OPS+ first exceeded 1.000 in 2017, but he just missed qualifying for our list due to injuries. However, you're about to see him a good bit more frequently, as we move to the "back to front" peak performances.
As noted, there are only 17 of these in the 2010-19 decade: the July-to-June slice has some kind of "whammy" on it that results in about 30-35% fewer of these peaks than in the standard April-September season. Some of this could be the oft-cited "salary drive" where hitters push for a bit finish to maximize their chances for a raise, but this is probably less prevalent in the age of multi-year contracts (especially likely for players who are performance at or near these offensive levels).
What's interesting is that we do pick up some players who didn't show up in the "front to back" listings:
Say hello to Ryan Braun, Buster Posey, and Nolan Arenado, who cracked through the glass ceiling via a July-to-June "salary drive."
Players whose names are in italics have a "front-to-back" season adjacent in one way or another to their "back-to-front" achievement here. You can see that Mike Trout, with four appearances on this list, has two "back-to-front" peaks that are exclusive to this list: 2013-14 and 2015-16. Most of these seasons do link to a "front-to-back" season, however--the only other exception is Joey Votto, who breaks through in a "back-to-front" in 2011-2 that is unique to this list.
Interesting to see a 54 HR peak for Christian Yelich (2018-19, giving him the highest season-length OPS on either list), 58 for Jose Bautista in 2010-11; J.D. Martinez hitting 58 as he moved from the Tigers to the D'backs to the Red Sox in 2017-18; and Miguel Cabrera's 53 HR peak in 2012-13, accompanied by that 159 RBI total that's straight out of the 1930s.
Someone might want to look at the ages of these players in each list, and you also might want to follow what happens in parallel in the years (both "front-to-back" and "back-to-front" that follow these peak performances. (We might just do that a bit later in the waning days of the 2019-20 off-season.)
And--you may be wondering: which players had a hot second half of 2019 that might be putting them in position for a 1.000+ OPS for 2019-20? Yes, we have that data for you right here:
Three Astros on this list--there has never been an instance where three hitters from the same team have had a 1.000+ OPS, either "front to back" or "back to front." Can the Astros wean themselves away from their "kick the trash can" fetish and set a record they can call their own? We'll know the answer on July 1st.
Oh, and who's the "Three True Outcomes" leader here? HRs, walks, strikeouts--next to "beauty is truth," etc., "all you need to know" about baseball (and the fact that John Keats couldn't hit the curveball)? The answer helps take the wind out of Christina Kahrl's boast of coining this overrated concept: it's the man with the blue square--Eugenio Suarez, who reminds us that "TTO" numbers are rising because strikeouts--the most useless portion of this tendentious troika--are on the rise at a rate that dwarfs even the juiced, launch-angled tater tot travesty that was 2019 (and will, in all likelihood, be a blight on 2020 as well).
So in light of that, root for Ketel Marte to somehow replicate his .356 BA for the first half of the upcoming season and join our "back to front" list the hard way--with an ISO value under .300. He, Mookie Betts, and (surpisingly) Christian Yelich are the only three hitters in a position to do so. It used to be a common occurrence, but the last half of the 21st century has been brutal in so many ways that not even an ultra-fast computer can keep count.
