In 2017, I did significant research into age and development curves. I have continued to do the necessary research each year just to confirm the initial findings. At the outset, let me state that I do not rank, analyze, or in any other way deal with international prospects. As such, the vast majority of this research is on players who played in college.

The big takeaways:

1. Stars played their first NBA game at all different ages. There is no evidence that only young players will become stars, and there is no evidence that older players cannot become stars.
2. There is no evidence that college year matters in any way whatsoever. Almost every draft site uses college year rather than age despite the fact that age within a draft year can vary wildly. Age curves held steady regardless of what age a player exited college at. They did not map on to years out of college at all. Based on limited research, it appears that international and non-college players followed the same curve.
3. With very rare exceptions (mainly offensive big men), players were bad before age 20, developed into better players between ages 20 and 22, took a big leap at age 23, showed steady growth through their mid 20s, then took another leap sometime between age 26 and 28. Players occasionally took their first leap at age 22 or 24 instead of 23, but judging any player before they turn 23 is a bad idea. Bad players really can become good almost overnight.
4. Age growth curves held steady regardless of final college year or international status, bad players, good players, etc. These curves held for the vast majority of players of all types.

So, when approaching the draft, it is highly important to look at each player’s age. An 18 or 19 year old will not be as good as a 20-22 year old will not be as good as a 23+ year old. If you don’t properly put their college seasons into context, you can end up far too high or low on a prospect. You can also think they are closer or further from contributing than the actually are.

Project Players

One thing I have been particularly interested in is how often college “project” players panned out. From 2012-2015, 13 players were drafted outside the top 5 who played their first game before they turned 21 and have made any kind of impact. Those players are Looney, Jerami Grant, Winslow, Myles Turner, Booker, Gary Harris, Randle, LaVine, Steven Adams, Drummond, Harkless, Barnes, and Caldwell-Pope.

Looney: Drafted 30th overall. Barely played his first three seasons. Fourth year option was declined. He re-signed with the Warriors after getting no interest in free agency. Took a big step forward this year, when he will be a UFA. Age 23 is next year.

Grant: Drafted 39th overall. Played poorly for two seasons for the Process Sixers before being shipped out for the expiring Ersan Ilyasova. Took an age 23 leap big time for the Thunder.

Winslow: Drafted 10th overall. Took a big leap forward in his age 21 season after missing most of his age 20 season. Age 23 is next year. Signed a 3/39 extension.

Turner: Drafted 11th overall. Took a big leap from age 19 to age 20. Age 23 is next year. Signed a 4/72 extension.

Booker: Drafted 13th overall. Took a big leap at age 21. Signed a massive extension last offseason that already looks like a major albatross unless he takes multiple steps forward on both ends of the court. Age 23 is next year, so there’s a chance.

Harris: Drafted 19th overall. Took leaps forward at age 21 and 22. Got a big extension prior to his age 23 season, but he has regressed in each of the past two seasons, and that contract doesn’t look very good anymore.

Randle: Drafted 7th overall. Steadily improved leading up to his age 23 leap. Lakers renounced his rights after the season, and he signed elsewhere. He will be hitting free agency again this season.

LaVine: Drafted 13th overall. Appeared to be improving before tearing his ACL. Traded as the centerpiece in the ill-fated Butler trade. The Bulls allowed him to hit RFA before matching a contract. Took an age 23 leap, but needs to improve significantly (and stay healthy) to live up to his contract.

Adams: Drafted 12th overall. Took his leap more at age 24. He worked out. Good!

Drummond: Drafted 9th overall. Also took his leap at age 24. He also worked out!

Harkless: Drafted 15th overall. Traded in 2015 for a 2020 second round pick. Took an age 23 leap and has earned the extension he was given.

Barnes: Drafted 7th overall. Made his leap at age 22. Warriors declined to match the contract he was offered in RFA. Barnes is picking up his player option because he has not lived up to it.

Caldwell-Pope: Drafted 8th overall. Also made his leap at age 22. Had to settle for two one year contracts after his rookie contract expired and will be back in free agency this year.

Why do I bring this up? With each passing year, more and more young players are drafted highly, and the hit rate on them outside the very top prospects is extremely poor. These are the best of the bunch. Of the thirteen, seven didn’t sign an extension with their original team due to being traded, renounced, non-renewed, or non-matched (though this includes LaVine who was part of a major trade). So far, only Adams and Drummond have lived up to their extensions, and Harkless has lived up to his smaller one. Winslow and Turner could join that list, and Booker and LaVine could still grow into theirs, but we don’t know that yet. Only Harris, Grant, and Looney had any success outside the lottery – Grant for his second team, Looney after being non-tendered, and Harris hasn’t lived up to his extension.

Missing What The Draft Is All About

So why are there so many young players being drafted when they almost never work out? Either because they’re not good enough in the short term or because they need to be extended before their actual value is established, these players just never seem to work out quite right. The centers did have a higher hit rate among players who worked out at all, but only the lottery ones worked out at all.

One of my favorite draft quotes actually comes from the NFL Draft: “It’s obvious to me right now that the Jets just don’t understand what the draft’s all about.” NBA teams just don’t understand what the draft’s all about, it seems.

Many of the players I have been too low on over the years have been these non-top 5 U-20 prospects (though I had both Winslow and Turner top 5). Their hit rate is low, and when they do pan out, the second contract problem is an absolute nightmare, leading to average players getting well above average contracts. Excluding international prospects, I am aware of only two star players who played their first NBA game at age 20 and were drafted outside the top 5: Paul George at 10 and Kawhi Leonard at 15. Both were elite mid-major prospects who were good enough to get drafted top 15 out of small schools.

These players are just traps, pure and simple. You never get anything positive from them in their first season. You occasionally get decent or even good play from them over the next 2-3 years. And then you either have to overpay them or lose them. Once you get outside the top 15, you rarely get anything at all. Prior to Gary Harris, the last college player who played his first NBA game at age 19 or 20, was drafted outside the top 15, and signed an extension with the team that drafted him was Avery Bradley, who was drafted 19th in 2010. The last one drafted outside the top 20? DeAndre Jordan, drafted 35th in 2008.

These aren’t projects. These are ticking time bombs. The ones that work out, which again, are already the minority, end up getting overpaid. The only ones who don’t are the true stars and superstars, who can’t be overpaid because of the max contract limit, and centers, who tend not to get overpaid simply because there is not a huge need for centers across the league.

“It’s a dangerous thing to think you are smarter than everyone else.”

This was recently said about the Mets’ draft, but it applies equally to the NBA draft. In taking a young college player outside the top 5, a team is saying, “Yes, everybody else has gotten burned, but we won’t.” In taking a young college player outside the top 20, a team is saying, “Yes, every single one of these has failed for the past decade, but this is the one that won’t.” There can always be exceptions. Drafting for the exception is bad drafting.

From 2008-2014 (the last year that has hit free agency off their rookie contract), seven European players and ten older players drafted outside the top 20 signed extensions with their original team, with another two signing extensions but after shorter rookie contracts. So this isn’t an “all players fail” thing. This is specific to one type of player.

As a final note on development, most non-centers improved their shooting in line with the rest of their development, especially taking leaps around age 23 and age 25. Most centers improved their defense in this time. It was far more rare to see non-centers develop their defense in meaningful ways. Centers developing outside shots didn’t appear to follow a pattern, though the ones that do tend to develop it later in their careers. That may change as younger centers practice shooting far more than they used to.

In Sam Vecenie’s most recent mock draft, 11 of the 40 selections outside the top 20 are college players who will be 19 or 20 on opening day. Last year, there were five. The year before, there were eight, only two of whom are notable in any way (Jarrett Allen and OG Anunoby). In 2016, the only notable one was Dejounte Murray. Again, it is practically impossible to hit on these guys, and even when you do, you tend to get a roleplayer who you will have to overpay when they finish their first contract, if they even finish their first contract with you.

When it comes time to do my final big board, this issue will be reflected. Again, there can and will be exceptions. You will occasionally find a playable young player. But even when you do, you still run headlong into the second contract issue. This is an easy to avoid trap, and the fact that teams still fall into it year after year after year is truly mind-boggling.

Previously: The Past, The Present, The Future | Next up: On Patience and Probability