Horford isn't a superstar. He isn't a top ten player in the league talent.
But he is a great player.
If you look at the three main advanced metrics that can be found on basketball-reference.com, WS/48, BPM, and VORP, the players who are closest to him in value across all three are probably Jimmy Butler and Damien Lillard. I'd be very willing to believe he has been equal value to those players this season and probably will over the next couple of seasons.
I like advanced metrics, but they aren't the only things I go off.
You give me a choice between Jimmy Butler, Damien Lillard and Al Horford - I can assure you Horford wouldn't even made the conversation. Butler and Lillard are far, far superior players.
We need to be careful not to take advanced metrics out of context. Their aim is not to tell you how good or talented a player is, they exist to tell you how much better a team is with that player on the court, versus when he is not on the court.
It's important knowledge to have, but a great RPM (for example) doesn't suggest that somebody is a great player.
For example, Al Horford has a +3.28 RPM.
By comparison:
* Jared Sullinger's RPM is +3.25
* Jae Crowder's RPM is +3.02
* Kelly Olynyk's RPM is +3.00
* Amir Johnson's RPM is +2.81
Would you say that those four guys are all as good as (in Sully's case), or very close to as good as (in Jae, Kelly and Amir's cases) Horford? If the advanced stats are all you go off, then it would be stupid to sign Horford to a max when we could get either of those four guys playing the PF spot for far, far less money.
I mean hell, Sully doesn't only match Horford on the advanced stats (RPM, Net Rtg), he also is right up there with him in the box score stats too.
Obviously we all know Horford is a better player then Sully overall, but there are certain things we know that stats can't back. And that is coming from me - somebody borderline obsessed with stats lol
Horford is correctly a #2 guy (after Millsap) on a good, but not great, team. Even with him as a #2 guy, that Hawks team isnt good enough to be a contender.
This Celtics team is just as good as that Hawks team (identical regular season record) and so making Horford a #2 option on this Celtics team also will not make us a contender.
If we can get a legitimate star player (e.g. Durant, Cousins) who can take over as our #1 guy, then we can put Thomas down as our #2 guy, and bring Horford in as our #3 guy. I think in that type of scenario he can be really effective, and we could be a contender. But even then our window is very short, because Horford is already visibly declining (you can see it not only in his stats, but from watching him too) and isn't likely to last more than another year or two at his current level of productivity.
So even then you need to ask yourself - is it worth paying something like $100M over four years just to give yourself a one or two year window of contention? That's basically what Brooklyn did with the KG/Pierce trade, and we can see where they ended up.
There is certainly no point wasting $25M a year in cap space on the guy unless you know for certain that you are getting that #1 guy - because without that guy, Horford doesn't make us that much better then we already are. He's an incremental upgrade, not a revolutionary one.