Jeff Green is a pretty good asset, someone who makes reasonable enough money and has enough talent to at some point possibly be a part of a package that would fetch the Celtics an upgrade, either for more talent or more picks.
But as a player, Jeff Green is extremely underwhelming. Which is fine; he is what he is. But Celtics fans overvalue him massively. In a recent thread, various people claimed that he is more valuable than an 18th pick or a pick in the 20s. Those people are wrong. Perusing the recent draft history shows that the 18th pick offers the potential for the Celtics to seriously upgrade over Green.
The 2012 18th pick was Terrence Jones, who is filling a role in Houston that Green was never able to fill in OKC. Yes, he might be a limited player who only works in certain systems, but is that any worse than Green, who does many things--except rebound and pass, which he's abysmal at--pretty well but excels at nothing? We now know that Green does not have the skills to be a number-one or number-two option on the roster, but we also know he's not capable of being the third or fourth player on a team. He's probably a better overall player than Jones, but he's certainly not any more valuable.
And then there were the 2009 and 2010 18th picks: Ty Lawson and Eric Bledsoe. Oh my. I think it's safe to say that any right-thinking fan would trade Jeff Green for either of those vastly superior players in a heartbeat. Same with 2002 18th pick David West.
It's true that I have been somewhat selective, and it's also true that the strikeout odds are higher at 18 than at, say, 9. But look at some of the others picked at 18 who have made an impact: Marco Bellinelli, JR Smith, Javale McGee, Gerald Green. Each of those guys has definite flaws, but they also excel in certain parts of the game in ways that Green does not. Again, Green is probably a better overall player than each of them, but I wouldn't definitively say he's more valuable than them.
As for later picks, here are some names of players picked in the 20s going back to 2006: Sullinger, Faried, Reggie Jackson, Taj Gibson, Ibaka, Batum, George Hill, Dudley, Afflalo, Splitter, Rondo, Lowry. Again, every one of those players is better, and more valuable, than Green.
Yes, the odds are stacked against developing such late picks into valuable players, let alone superstars. Which reduces the issue of trading Green for late-first-rounders down to two questions: First, does Green have the skills to make the risk inherent such a deal absolutely not worth it? The answer for me is certainly no. He doesn't create his own offense or offense for other people, so he's never going to be a superstar or a top-2 player on a contender. But he also lacks a definable skill that makes role players so valuable: he's not a three-point specialist like Bellinelli or Jones, or a lockdown defender like Bledsoe. He's just average at all those things.
The other question is: Do you trust Ainge to draft talent at that position in the draft and do you trust Stevens to develop it? For me, the answer is yes. That doesn't make it a sure thing. For every Sullinger and Bradley there is a JaJuan Johnson and JR Giddens. But no team hits them all, not even the Spurs.
I'd gladly sacrifice Green for the gamble of possibly landing a Bledsoe.