the damage to Cleveland is much worse when you look at the +/- ratings. Replacing a +12.8 player with a +0.0 one in 2966 MP would take a +7.1 efficiency differential team down to a -2.5 one. Which teams had roughly a -2.5 differential last year? The Raptors (-1.9, 40 wins), Hornets (-2.7, 37 wins), and Pacers (-3.1, 32 wins), meaning SPM sees the Cavs finishing in the lottery without LBJ. And APM's story is even more terrifying for the Cavs: losing a +18.1 player would knock a +7.1 team all the way down to a -6.5 team, which is 2010 Clippers territory. And that's if they can replace him with an average player.
Or maybe it would make things easier if we just looked at the way Cleveland played last year when James wasn't on the floor: they were -4.7 in efficiency, akin to the 2010 Kings, Sixers, or Wizards (compared to +11.1 when he was on the court). Obviously all of these scenarios are simplified models based on many assumptions, but one conclusion that you can count on is that the Cavaliers will be nowhere near the top seed in the East if they can't convince LeBron to stay in Ohio. In fact, if you believe the +/- ratings or the on/off numbers, they probably won't be anywhere near the playoffs without the King, either.
So for Byron Scott's sake, I think it's safe to say he'd better deliver the sales pitch of his life this weekend. Otherwise, he could find himself wishing he was still coaching the Hornets, or even broadcasting for ESPN... Both of those gigs are more appealing than piloting a glorified version of the Clippers.