WALTHAM — On Wednesday, the NBA finally acknowledged reality and dropped the center position from the All-Star ballot. Now fans will vote on two guards and three “frontcourt” players. Celtics  coach Doc Rivers , who is a member of the league’s competition committee, said that he pushed for more changes to the process.
“I just think it should be 12 guys,” Rivers said, meaning regardless of position. (He also hinted that All-Star roster may be expanded to include 13 players.)
The All-Star switch is a modest reflection that the NBA is in the midst of a slow and steady evolution away from traditional positions and the Celtics are right in the middle of it. Consider their starting lineup, which has remained a mystery throughout camp and will likely continue to remain one throughout the season.
Rajon Rondo  is the point guard. Paul Pierce  is a forward who plays on the wing and Kevin Garnett  is the big man. After that, Rivers could start Jason Terry  or Courtney Lee  in the backcourt. When Avery Bradley  comes back from shoulder surgery he’ll be in the mix, as well. Bradley guarded the other team’s point guard on defense, but played off the ball when he was on offense. Rivers has already said that he doesn’t have a backup point guard, he has four of them.
Up front, Jared Sullinger or Brandon Bass  could start. Even a true big man like Darko Milicic  could get a turn with Garnett getting a breather against some of the true remaining centers in the league.
“I think it’s pretty simple to figure out your starting lineup although this is going to be an unusual team in that I don’t think we’ll have a starting lineup for most of the year,” Rivers said. “We may move that one guy around quite a lot.”
Then there’s Jeff Green , who is not being considered for a starting job. He will do something more valuable. Green is expected to come off the bench and if the preseason is any indication, he’ll get about 25-30 minutes a night playing both forward positions. He’ll even work with Pierce in lineups where the whole concept of positions is completely meaningless.
“It’s completely gone,” Green said. “We’ve got guys who can multiple positions. When we go out there, we’ve just got to play and play together. There’s a lot of team playing small ball right now. You’ve got to be able to matchup with them if you’re going to be able to win. We have the ability to do that and we can matchup with any team. If that’s what they want to do, we’re prepared.”
In an ingenious twist, the Celtics are taking a player whose primary weakness is that he has no defined position and are simply turning him into a basketball player.
“He just helps us,” Rivers said. “He’s a valuable player.”
Take the lineup with him and Pierce on the court together. Is one a three and one a two? Actually, neither. Against the 76ers on Sunday, Pierce guarded Jason Richardson  while Green drew Evan Turner .
“The two and the three are the same position,” Rivers said. “That’s easy for us. They run the same stuff.”
The idea isn’t necessarily to matchup with other teams, it’s to create mismatches in your favor.
“You want to create more of a matchup game, you don’t want to be the guy matching up,” Rivers said. “That usually means they got the best hand. But you can actually create matchup game on certain nights. Not every night but on some nights you can.”
Rivers likened his current team to his 2008 championship squad in that he simply chose the five best players and put them on the court together in the fourth quarter. The key to that team was James Posey , who guarded multiple positions. While they are different players, it’s the same concept with Green.
It would be foolish not to acknowledge the looming specter of the Heat in all this. Once they decided to move on from playing a traditional big man, it freed up LeBron James  to reach new heights in the postseason and the Celtics had no good answer for them once Chris Bosh returned to solidify the frontcourt.
“It’s almost like they had to work their way to that,” Rivers said. “During the first round and the second round they were trying different bigs and then finally they just said, ‘Our five best players are going to be on the floor.’”
It remains to be seen if the Celtics have the right answer for Miami, but at the very least they have a better one than last season.