(This article initially appeared at LibertyBallers and is reproduced here for completeness only.)

Hey folks, welcome to the first official collaboration between Don Yates and Buster Ducks. If you don’t know us, we’re both long-winded, statistically minded draftniks. Don typically posts here in the LB Fanposts, Buster typically posts on his website, BusterDucks.com, or at DeepishThoughts.com. We’re trying this out for the first time, so suggestions are welcome, and if you want us to cover a topic, you can comment down below or you can tweet us, @DonYatesNBA and @BusterDucks.

So, as Buster doesn’t like to talk about individual prospects this early in the college season, these early conversations are going to look at more theoretical/philosophical topics related to the draft. Given that this is “The Year of the Freshman” and the new CBA just got ratified, we (well, Buster, really) decided that a good first topic is the one-and-done rule, specifically as it relates to projecting prospects and players. Let’s get to it!

BD Initial Thoughts:

So, I actually suggested this topic because I’ve been thinking about it in relation to two guys drafted in 2016 – Brandon Ingram and Malcolm Brogdon. Brandon Ingram has been abysmal. Brogdon has been one of the top 3 players from this class so far. Brandon Ingram is 19. Malcolm Brogdon is 24. It’s just unfair to compare the two. But in this day and age of instant draft analysis, we’re constantly asked to do just that. There’s just no patience. Even teams feel pressured and compelled to play highly drafted but very young rookies instead of sending them down to the D-League where they belong. So what’s the problem, and what’s the solution?

I look at the guys who were drafted as HSers, and it’s hard to find a single player who was particularly effective before age 20 – we’re not talking about keeping superstars from being superstars here. But looking at how it worked out overall…there’s certainly no evidence that it was harmful. Of the 39 players drafted out of HS, there were 10 all-stars and numerous other impact or long-term NBA players. Only 6 were complete busts, and there were a couple of other guys who didn’t pan out but who had something of a career.

So, I guess changing from HS to one-and-done was to get more ready-now players. Instead, we are getting a whole bunch of freshmen who aren’t panning out. You look at the top players in the NBA, it’s hard to even find guys who were drafted as Freshmen…Durant, Boogie, Davis, Wall? Conley? Did we really need college to find out that Durant, Boogie, Davis, and Wall were going to be great? What is the one-and-done doing? By results, it’s hurting these guys (and NBA teams) more than helping them. This isn’t the best way to do this. I feel confident saying this. Quite frankly, teams only play 5-6 games against high enough level competition to show anything. Even 35 games isn’t enough to really show anything meaningful. So now instead of drafting guys based on HS tape and then molding them, teams (and analysts, like us!) are left to draw conclusions with incomplete or bad data. I know Don has some thoughts on what would be best, and since I don’t have a strong opinion on the optimal system here, I’ll let him go first. Don?

DY Initial Thoughts:

Well, my thoughts here are really just that I do not know. Projecting basketball is so difficult – more than being an incomplete science, it is just hard to know future mental makeup in completely unpredictable situations and impossible in every respect to know what will happen in these real people’s lives to affect their performance and development at their job – their career, which could end in one year or in twenty, depending solely on these impossibly unforeseeable circumstances.

But I do have a few well-considered ideas, hypotheses, on the topic. Before diving in, let’s first look at those 39 players you mentioned who were drafted straight out of high-school between 1995 and 2005:

The most staggering thing, of course, as it seems to me, is that the first four players drafted out of high-school in this period, despite being selected 5th, 13th, 17th and 9th, turned out to be two-way superstars in the NBA. This is … a higher hit rate than one should expect out of these draft slots. Overall, 10 of the 39 (or 25%) would reach NBA star or superstar status, which is an extreme hit rate for even top-three picks, let alone guys being selected much lower than that, as over half of them were. Of the remaining 29, I judge 10 of them as having made a significant NBA contribution at some point in their careers, being at least starter-quality. Of the remaining 19, there were some 10-year careers and some rotation-level players at some point in their careers, but they can largely be categorized as busts (among the lottery guys) or simply insignificant players (among the rest).

If you’re drafting with rough odds of a 25% chance at a star or superstar, a 25% chance at an eventual starter, and a 50% chance of a low-level rotation player, you are looking better than almost every non-No. 1 selector in NBA history.

There was also a clear trend from the first eight years to the last three years of many more players declaring, with 22 of the 39 coming from those three years; I am not sure, looking forward to a hypothetical world, whether or not this (~seven or eight players declaring straight from high school per year) would be the norm, or if 1995 to 2002 (~two or three per year) would be closer to it. The factors which would influence that would probably be the exact rules.

The most frequently discussed potential rule change with the recent CBA with regards to draft eligibility was the so-called “2-or-0” rule, with prospects being able to declare for the NBA draft straight out of high school (as long as they turn 18 in the draft year), or being forced to stay at least two years in the NCAA, if they decide to go that route. (They would still be able to sign with the D-League or overseas for just one year if they choose to do so.)

Since I haven’t formally declared my general thoughts, I will say here: I am a fan of this rule. I am a fan of true NBA prospects being able to get into the NBA at 17 or 18 or 19 years old as opposed to at least one year later. This is an incredibly vital period of mental, physical and skill development in players, and I am firmly of the belief that it is harmful to delay the NBA in all areas for prospects – general development in an environment with tenured professionals (being able to dedicate all of their time to improving their basketball abilities, as opposed to being weighed down with classes, tests, et al), world-class strength-and-conditioning coaching, help from nutrition specialists, and being observed and developed by NBA-level coaches.

There are counterpoints to this hypothesis which I’ll get into next if you don’t do it for me, but since I’ve taken up a good amount of space already, I’ll let you get to your thoughts here, Buster.

BD: Of course I have counterpoints!

Is there an ideal number of High Schoolers you want entering the draft each season? Looking back, it doesn’t appear that the number declaring had a significant effect. Teams actually did a great job identifying top talent, with the best HSer in each class drafted first or second among high schoolers drafted. And even in 04 and 05, there were a bunch of guys who significantly outperformed their draft position. Only 3 out of 17 guys were complete busts. That is tremendous. I think based on that data, limited as it is, it seems unfair to cap how many high schoolers get drafted in a given year. Clearly, that route was extremely successful. And it’s strange, but there were many years there where freshmen were not highly drafted, because teams didn’t like the wait. And then more recently, you see a lot more freshmen drafted highly…but outside the top 3, not to great results. Lessons of the past have been lost. But I don’t think one of those lessons was “there are too many high schoolers entering the league each year”.

As you may have unintentionally pointed out, age matters more than years out of high school. So I think any system needs to be age-based, not years-based. In fact, I think the 1-and-done rule is the worst of all worlds. It provides too small a sample to be useful, but enough of a sample that you can’t ignore it, so you’re left grasping at weak conclusions. It allows some players to hit the NBA at age 18 while others don’t hit until age 20 based on how quickly they moved through lower grades. And as you mentioned, ages 17-23 or so are a period of tremendous mental and physical growth, and instead of having one smooth transition from High School to Pros, there’s now this one aberrational year where they’re big man on campus, with a full year to develop really bad habits and learn all the wrong lessons, while playing basketball that bears only a faint resemblance to NBA basketball (shorter 3 point line and no defensive 3 seconds means that both offense and defense are totally different). I do think it’s hurting them.

But please, we do NOT need fucking 17 year olds in the NBA! Are you serious with that? C’mon man, you’re smarter than that!

Fans are impatient. Teams are impatient. Hell, players are impatient. So top prospects end up playing sooner than they ever should. I think any system needs to protect teams and players from themselves. And the overwhelming evidence is that, once a decade or so, a player puts up a meaningful age 19 season. And by “meaningful”, I mean “good enough to be a mid-level starter”, not “good enough to be top 3 on a good team or elevate a bad team”. Even age 19 LeBron only got the Cavs into the mid-30s in wins. You’re not losing anything by cutting out all teenagers. And so I think a prerequisite of any system is that it forces NBA teams to wait until players are at least 20 to put them on the hardwood.

So to me, any system designed to maximize the effectiveness of players and quality of the league has to involve a minimum age for players to play in the NBA. At the same time, I think it also has to involve a stronger developmental league, and a concerted effort to make fans, players, and teams alike understand the importance of proper development time. Now, personally, I’d love if we eventually ended up with the European model, where top prospects are identified and funneled into top prospects by the time they’re in middle school/high school, but I don’t think that’s something reasonable or likely to happen. So here’s a proposal…

What if players could be drafted if they turn 18 (or 17, but I really think that’s too young) by a certain date (October 31?), but they can’t play in the NBA until they’re 20? Maybe something like players are only eligible for the major league roster if they’re 20 by October 31, or can be called up midseason if they turn 20 after October 31 but before April 30? This is just me spitballing here. It would allow teams to develop players properly while also forcing them not to rush players who aren’t ready (like Brandon Ingram, who really got me thinking about this in the first place) and keeping fans off their back who want to see prospects before they’re ready to contribute. Just an idea.

DY: From the top: no ideal number of high-schoolers, no – my only point there was that recruits ranked lower and lower began entering the draft, and thus that could’ve been muddying up the results. (Also could’ve allowed eventual long-time NBA guys like Monta Ellis and Amir Johnson to slip through the cracks? Works both ways.) I agree with everything you said next, making the rules age-based and so on, and that one-and-done is obviously the worst of all worlds.

Andrew Bynum was 18 years and 6 days old when he made his NBA debut. Kobe Bryant, two months older than that, etc. I think there’s a very good chance that these players’ getting into their NBA teams’ systems at age 17 and whose being exposed to NBA action at such an incredibly young age significantly contributed to them becoming two-way superstars within a few years’ time. I think it should be at the discretion of the teams whether or not these guys see NBA action; I realize it is probably not great to watch for fans. But in the long-term, we might get 1) earlier-developing, 2) more and 3) better superstars in the NBA. It’s just one hypothesis which is very loosely supported by the small sample of data we have to work with.

If we go the opposite direction, and delay NBA debuts of players and force them into a D-League of sorts – which would really just be a glorified league of freshmen, sophomores and shitty older players at that point – I think you do risk getting 1) later-developing, 2) less and 3) worse superstars in the NBA. You may get a greater overall quality of play from all players in the long run; I don’t know enough to say otherwise. But I would risk a lot to ensure the quality and amount of superstars in the NBA keeps thriving and growing, forever. Fans will always rather watch the current Thunder and current Rockets than the superior team-play of the Hawks of 2014-15.

In a recent e-mail exchange with Kaiser/Rubes (formerly of LB fame), he posited the direct opposite to me: that younger unrefined players will be pigeonholed into specialist roles because that makes them useful sooner, while players who attend college for three or four years are given time to fully flesh out their all-around skillsets and act as team-leaders. As much as I respect and truly value his opinion (as I’m sure he and even many of you can attest to), I think the evidence before us simply proves the opposite. We have a 25-percent hit rate on developing high-schoolers into superstars, and, while this is highly unfair, something like a 0.1-percent hit rate of all upperclassman college player draftees becoming superstars. There is no true fair way to look at this – by in large, the guys who became superstars simply got into the NBA the earliest they possibly could (whether from high school or after one year in college), and we have absolutely no way to distinguish a case of real development from a case of true talent between the two groups of prospects (though it’s all a mixture of both in the end).

So I revert to approaching it logically: what’s better for the players? Resoundingly, the environment of having world-class helpers aiding you with developing every part of your game all of the time is a better one; resoundingly, being able to focus solely on one’s game as opposed to classes and tests and such is better for one’s development; resoundingly, getting settled into one’s eventual environment earlier is better for a player’s long-term development. (There are so many anecdotes I have in mind, but I have to refrain from pointing to them. Perhaps in the comments I’ll have a chance to flesh them out with an overlay of my case being made here.)

Is there a happy medium between playing young players in the NBA and developing them optimally over the long run and giving the fans the best product possible? Any take on that, or anything else I’ve said, Buster?

BD: Well, your first concern is easily handled – in baseball, players not drafted or unsigned out of high school are still allowed to attend and play college ball. So if too many guys enter and some slip through the crack? They should show up at the college level soon enough. It’s not a perfect remedy, but would probably work well enough.

I just dove deeper into aging curves, looking specifically at the age in which the player entered the league. And what I found will shock you! Oh, you’re already reading this, I don’t need clickbait, do I? Anyway, I found a few interesting things:

1. Age in which a player entered the league had no effect on growth curve. I can’t even confirm there was a higher rate of injury. It really looks like, as far as overall growth is concerned, it doesn’t matter what age you play your first NBA game.

2. Pretty much without exception, players were bad before age 20 (there were a few age 19 backup quality seasons), took a leap at age 20 or 21, took another leap at age 22 or 23, and then basically all players showed either consistent growth through the late 20s or took another leap some time between 24 and 28.

3. Age growth curves held steady among stars, midlevel guys, low level guys, HS guys, one-and-dones, multiple college years, and foreign guys.

4. Age growth curves held steady across positions.

5. Players occasionally had an “adjustment year” (year below what would be expected based on their age and the rest of their career) their first year, but it was not common and did not appear to follow any pattern.

Now, I’m not going to say this is a perfect fit for every player, but as a prognosticator, I’m looking for high probability patterns, not 100% perfect fits, because they don’t exist. And I’m comfortable using this as a projection fit for now.

So, applying this to what you said, Bynum and Kobe basically fit this curve perfectly (Bynum got a bit weird because he basically only had one healthy season, but damn, looking at what he was doing early, it’s a damn shame he could never get himself healthy and happy playing basketball). I have no reason to believe that Bynum playing some really awful minutes as an 18 year old did anything notable for him. I also don’t think it caused his injuries. I really don’t think there’s any argument to be made that 18 year old seasons show literally anything other than that 18 year olds shouldn’t be playing in the NBA.

After that, it gets a bit dicey. Showing that you’re clearly an NBA player at age 19 is a great sign – pretty much all the 19 year olds I can find who graded out as at least backup quality at age 19 ended up being good or better (Jabari Parker is a recent example of a good 19 year old season who already took a nice leap this year and likely has another leap into top-3-on-a-good-team quality player in him). Using BPM as just a general baseline (trying not to get too technical or complicated here), if a guy has a BPM of -2.0 or better as a 19 year old, he’s likely a future star (and at the very least has a near guaranteed chance of being starter quality). If he’s between about 2.0-4.0 or so, there doesn’t seem to be a clear trend, and although better is better (duh), there’s guys on the low end of that who end up shooting up to roleplayer or starter quality, and there’s guys on the high end of that who never show any real improvement at all, but these guys will not be top-3-good-team quality. Lakers fans should feel excited about D’Angelo, who was -1.8 last year, because he actually had a great season (and I don’t think having a year under Byron Scott was good for him!). Once you get past that -4.0, you’re looking at a guy who most likely never becomes better than backup quality, if that. Sorry for that brief optimism Lakers fans, Ingram’s at -4.4.

So, I mean, I’m going to go with Rubes here. There’s a bit of a problem of proving a negative here, because to counter your position is to show that stars who entered the league young would have failed to be identified or failed to become stars if they didn’t enter the league when they did, but the top NBA stars were almost uniformly identified as top prospects in high school and were highly drafted, and based on the NBA-wide growth curves, there’s just no reason to believe that starting your NBA career later would have any negative effects or create lesser-developing, worse, or less superstars. In fact, I think Rubes is dead-on here.

What I’m seeing more is that teams (and fans) are too quick to judge players based on age 19 (and even age 20-22) seasons that are not representative of a player’s peak talents. I’m guilty of it myself. There is a bad tendency to look at what a guy does early in his career and use that as a baseline of his true talent level, when true talent level really is not established until age 23 or even later. So you have guys who end up with bad reputations (Russell and Tyus Jones come to mind) despite doing absolutely nothing wrong and end up regarded far less than they should be because they just entered the league too early, while somebody like Malcolm Brogdon, who is playing like a backup PG right now, gets praised for nothing more than being a competent 24 year old because he’s a rookie.

And it just hurts everybody. Older (20-23 year old) players coming out of college never get the looks they should just because they weren’t highly touted and had a spikier growth curve. Younger (18-20 year old) players coming out of college with a lot of hype but before they’re really ready get tossed to the side before they’re fully formed. The only players teams are really identifying well right now are true can’t miss guys. Teams are discarding young guys for not being ready at an age nobody’s ready at, and teams are significantly underdrafting, underplaying, and giving far too few looks at older guys who had big talent spikes a little bit later than guys who had flatter growth. So we’re missing talent on both ends…for what? Nothing. Literally nothing. That’s a problem.

So, looking at it and thinking about it, I don’t think using rules to manipulate the way teams and fans think is fair, so I’m going to retract my previous suggestion and simply offer that there’s no reason to bar high school players from being drafted. There just needs to be a concerted effort to be smarter about prospect and player evaluation that properly accounts for age and the different growth rates of different players. And even though allowing high school players in make statistically-based draft analysis harder, NBA teams have actually shown aptitude in identifying and developing talent in that realm, so I don’t see a problem.

I think that’s just about all I have to say about this. I’ll let ya take it home, Donny – don’t bring up anything else that gets me thinking and researching, this is already pushing 4K words!

DY: Interesting stuff. On your notions of age of entry into the league not having an effect on growth curves, I would like to reference a few things which posit the direct opposite. Here is a 2014 article from Scientific American entitled What Predicts NBA Success? which consistently states much the opposite, saying:

Unsurprisingly, measures of physical makeup and athleticism (e.g., arm span and agility) did predict draft order. These variables clearly influence selection into the draft. But crucially, physical makeup and athleticism did not distinguish productive NBA players from unproductive players after taking into account prior performance.

In fact, the only variables that predicted NBA success were youth, college performance, and college quality. These variables predicted NBA performance better than draft order. What’s more, while younger players were more productive in the NBA than older players, younger players were not, on average, better in college than older players.

This has huge implications (I first found it during the 2015 draft season, and have been loosely preaching and practicing it since then). The full study it is citing can be found here. The main takeaway here, unrelated to the topic at hand, is that physical tools have no predictive value towards NBA success (measured in win shares) when controlling for college success (also measured in win shares). Age, however, does. This is consistent with other studies done on the topic – see this one as well, which uses the NBA to argue that age of entry into elite-level professions leads to better career outcomes – and is also consistent with my general ideas above.

The crux of my philosophy is that the younger a player gets into the NBA, into their eventual long-term environment, the higher their chance of reaching their peak of play and the higher their peak of play will be. The coaching, development, elite staff and professional environment is probably all more significant than actually seeing NBA time, but I think they come hand-in-hand. There are a handful of anecdotes which probably support the opposite viewpoint, but I am not taking the option of college away from prospects – if they want to go, they can go (I am okay with forcing them to stay two years) – I am just highly encouraging highly-touted high-school recruits to enter the NBA draft instead. In the future, the NBA’s Developmental League will certainly be much more expanded and the system I’m advocating will be adjusted to reflect that, and that’ll be great. That’s all for me. Take it away, Ducks.

BD: I actually agree with that study in its entirety! And I actually think it agrees with me! What that study shows more than anything else is that teams and colleges, as a whole, don’t let top talent slip through very often. So, if teams (and colleges) are identifying top guys that early, just let them into NBA systems that early! And of course older college players outplayed younger college players! It matches up with what I said above. So basically, top tier talent is generally identified early, but takes some time to develop. I just don’t know that you can say that getting into the NBA younger leads to better outcomes – I think studs will be studs, and I honestly think that going to a good college program is better or at least no worse than going to a badly-run NBA team, and teams drafting at the top tend to be badly-run. Basically, we have no way to study if LeBron becomes LeBron if he had gone to school for 3 years first. But I highly suspect he would have had the same career overall, and I suspect that most elite players would be elite players no matter when they enter the league. But since it can’t be studied, we’re now into the land of pure conjecture, and that seems like a pretty good place to call this. Til next time, Donny.