Cheese In the Kitchen: Midseason Prospect Promotion Splits and a Death in the Family

“It’s the DJ’s job to get the crowd out of their head and into their bodies…
… in order to do that, you need – at the very least – a caveman sense of rhythm …
… and a cursory knowledge of mathematics…” – `We Are Your Friends’

The last data request I ever made of Rob McQuown came back from him about a week and a half ago, exactly to spec like it always was. Before we got buried in Midseason 50 content I had a thought about looking into the performance of minor leaguers who get promoted mid-season versus the second-half performances of players who stay at the same level all year.

Like most of my requests to Rob, it was half-baked when I made it. It was the starting point for a future conversation, like dozens of others before it had been. After kneading the dough together with him in a late night conversation, I slapped together a formal data request about how I wanted the raw numbers to look, with a couple paragraphs worth of instruction that kind of almost added up to a coherent outline. He asked me to clarify a couple things, and he rewrote my cave paintings into math, and then a couple days later he produced a perfect 105-by-21 data set covering every season and minor-league level we had available data on going back to 2005.

The thing about Rob is that he’d do anything for you. You too. And you over there, as well. He had a love for baseball, and a love for helping people learn, that I’ve rarely encountered on this Earth. If you wanted to get in with Rob? All you needed was curiosity and a question mark.

* * *

For this project we started by splitting each minor league full-season level (Low-A, High-A, Double-A, and Triple-A) from 2005 to 2018 into two buckets: position players who played the vast majority of the season at one level, and position players who got promoted up to a new level in the middle of the season. For the former group we determined to isolate a sample of hitters who logged at least 45 games at one level before June 15th and another 40-plus games at that same level after June 15th. And for the second sample criteria we used players who played less than 15 games at a level they then played at least 40 games at after June 15th.

This query produced just a hair over three million total plate appearances across a sample of more than 750,000 player games. The data’s a little hazy for the first couple seasons, with sets that appear incomplete for 2005 and no numbers available for levels below Triple-A in 2006, but I’ve included them here anyway, since they don’t really skew the topline takeaways. And the toplines indeed confirm a very basic starting-point hypothesis: players who stay at the same level all year perform better in the second half of the season, pretty much across the board, as compared to players who get promoted and have to adjust to a whole new time and place on the fly. They do it across a much, much larger sample of at-bats, too, because most players aren’t good enough to force mid-season promotions. Here are the aggregate per-level season averages for our two groups:

	G	PA	AVG	OBP	SLG	SOr	BBr	TAv
New Level	2,621	10,324	.264	.332	.398	19.3%	8.5%	.264
Same Level	7,149	29,413	.268	.336	.410	19.3%	8.6%	.268

The data is still in pretty raw form and I’ve parsed it really roughly to get here, largely because this is the stage of an inquiry that would still be fitting for its first dress rehearsal and not going live in an article. But at least thus far, the numbers drew the bottom line where I figured they would: the disadvantages of moving up a level, and the whole new set of challenges that brings – physically moving to a new city and likely part of the country; leaving teammates and established relationships in one place for an unfamiliar clubhouse and different coaching staff in another; facing pitchers you’ve never seen before who are way better than the ones you’ve been facing; 9.25 million other mundane differences in daily life – coupled with the advantages retained by hitters who stay in one place, get to make counter-adjustments and play veteran at the level, bank four-plus months of familiarity and routine, see pitchers for a third or fourth time, and so on…All of it produces a head wind, and the movers don’t do quite as well as the ones who don’t shake.

There is, of course, a gigantic selection bias at the core of this inquiry. The hitters who get promoted to a new level in the middle of the year are, very probably, the ones who earn it. They’ve gone out and balled for the first three months of the season, and in the vast majority of cases either their performance or their tools or both are such that their organizations want to see how they’ll hold up against stiffer challenges in the second half. Each of these players has taken one step more in progression towards the big leagues, and each one of those steps is a huge deal. It’s going to be a significantly more talented group of players in the “New Level” bucket.

There are related age considerations not captured by this initial ask, too. In a subsequent request I think I would have this data set revised to include a breakout of average player age relative to level, because that would be interesting. On one hand, you might expect that the players forcing promotions should skew younger. They are the most talented players, and the most talented players tend to be the ones pushed most aggressively. On the other hand, sometimes older guys just finally age out of their levels and need to bump up. Sometimes a younger, hotter-shit prospect at the level below forces a chain of roster moves that results in those kinds of promotions, too, and those situations will have infiltrated our samples. It’d be worth diving into that intervening variable, and we could’ve done a whole look at how players older than league-average fare versus younger guys getting pushed.

Then there’s a potential issue where limitations on the “New Level” specifications might be weeding out the most special, high-end prospects by penalizing them for earning multiple promotions in one season. That might be a problem with the initial data set. The three-level risers who spend a couple months in Low-A, a couple in High-A, and the rest at Double- or Triple-A won’t make the cut for inclusion among our second bucket. So maybe we’re creating some undue bias for or against our promoted set here. That’d be something to talk through.

And then, from the handful of re-sorting exercises I did, here are the average season samples broken out by level:

		G	PA	AVG	OBP	SLG	SOr	BBr	TAv
AAA	Same Level	7,505	30,619	.276	.342	.432	18.6%	8.7%	.269
AAA	New Level	7,377	29,513	.272	.338	.418	18.5%	8.6%	.264
AA	Same Level	8,139	33,146	.266	.337	.406	18.7%	9.0%	.269
AA	New Level	6,963	27,621	.263	.332	.397	19.0%	8.8%	.264
A+	Same Level	7,162	29,781	.268	.335	.409	19.6%	8.5%	.268
A+	New Level	6,457	26,286	.265	.333	.395	19.4%	8.5%	.265
A-	Same Level	7,904	32,890	.261	.329	.392	20.2%	8.5%	.267
A-	New Level	6,907	27,992	.258	.324	.381	20.1%	8.1%	.262

Okay, okay. Hitters get better as they move up, which tracks. It may be obvious, but I think we’d probably want to run this same query for pitchers to see just how much the inverse plays with them. Maybe the poor relative quality of lower-minors defenses distorts their numbers in weird and unhelpful ways? The new-level penalty is actually pretty consistent, and that’s kind of notable. Fewer players spend a full(ish) season in Triple-A these days, and, at least in the small year-by-year sample, it appears that front offices may have shifted in their handling of upper-minors rosters back in the late aughts. That might be worth exploring. Players don’t stay in Low-A as long now as they did when our sample begins, either. It’s entirely possible, if not probable, that both of those apparent shifts are nothing more than statistical noise. But these are other side streets that may lead to a cool speakeasy.

* * *

This is the part of the process where Rob really shined. Research begets more research. That’s the whole point. But it only does that if unbridled curiosity and enthusiasm pushes it forward. When I got a raw data set back from Rob I’d usually take a couple days to poke around at it and see what the numbers said. Then I’d send him a (quite unsolicited and long) string of additional half-baked reactions to it. X led to Y over here, but maybe Z was the reason? At some point in the next, oh, 12 hours, give or take, he’d respond with detailed thoughts on X, Y, Z, and like six other letters, usually having run another couple queries to see what story those numbers might tell.

* * *

That Zac Efron quote from “We Are Your Friends” I blocked up at the top is, verbatim, one of the last things Rob ever posted in one of our staff music channels on Slack. It is a prescient and fitting kind of poetry to his person. Efron’s character gives a long soliloquy in the quoted scene about the role of the DJ in rocking a party proper, and it’s a really quite shockingly well-constructed deconstruction of the art that the form requires.

DJs have to understand the room, really read the audience. Not to figure out what people want, but what they need. They have to be able to improvise, and turn old things into new things, to react and create. To draw on history and remember the parties they’ve rocked in the past and the sequences of beats and transitions that led to those rockings. To recall from the deep and unique archive of rocking tracks and combinations they’ve dropped on dancefloors far and wide. To know where in their busted-ass legacy crates with the worn duct tape and old faded band stickers that one record resides that they need to pull in order to rock this particular party at this particular moment. The DJ is both the life and library of the party, and the DJ alone – quietly, behind the mixer, anonymous and outside the fray – holds the key to the night.

A party is only as good as its DJ. It’s been bumping around here for the last decade, and right now it’s an eerie, bad kind of quiet.

Thanks to Rob McQuown for the research assistance.