The Perkins trade saga continues …

Former Celtic Kendrick Perkins swapped teams with Jeff Green in a midseason trade. (Elsa/Getty Images)

Boston fans adore Kendrick Perkins, which is why so much of the discussion over a trade involving a marginal NBA starter has been heated and sometimes irrational. Few trades centered on a guy who will almost certainly never reach All-Star status have created such controversy or been deemed so central to the fate of a team. It is not a stretch to say some blame the Perkins/Jeff Green swap for the Celtics’ postseason failure.

The debate reaches such extremes in part because the Perkins deal represents a clash between numbers and the ephemeral notion of “chemistry.” It is very difficult — and perhaps impossible — to find a shred of statistical evidence that the Celtics suffered a drop-off in play because they lost Perkins. (Remember: Correlation does not equal causation. The Celtics performed slightly worse after January, but they have mastered the late-season fade over the last few years. Pinning a late-season scoring decline over a small sample size on Perkins seems like a stretch.) But those who believe in the power of a positive, united locker room hold strong to the notion that the loss of a long-term centerpiece deflated the team in ways stats could never measure. It is an appealing argument, in part because it is impossible to disprove.

Rajon Rondo gives voice to that idea in this interview with Yahoo! Sports:

[Rondo] also believes the trade of Perkins, his closest friend on the team, affected the Celtics “more than it should have.”

“It wasn’t like the man passed away or something,” Rondo said. “I think we put too much emphasis on it. It’s a business. He got traded. He’s very happy where he’s at. We still talk and I’m always going to have his back. It shouldn’t have affected us the way it affected us.”

The Perkins trade has always struck me as something of a red herring for Boston fans trying to explain why their team flamed out against Miami in the second round of the playoffs. It’s a convenient excuse, an easy “what if?” scapegoat that ignores the context of the 2010-11 season and the Celtics.

Boston’s problem for two years running has been a below-average offense prone to team-killing dry spells. At best, Perkins was not someone who was going to help solve that problem; at worst, he was part of it. Toss in the fact that Boston was going to have trouble re-signing Perkins, and you get what the C’s were going for, especially considering the injury to Marquis Daniels left the team bereft of legitimate wing backups.

The issue with the deal has always been Green, on both sides. He was a consistent anchor in Oklahoma City; lineups featuring him almost always performed worse than those that did not include him. The addition of Perkins brought the Thunder a beefy, defensive-oriented center and cleared the power forward spot for Serge Ibaka. It was a double win.

The following things are also true:

• Perkins played just 313 minutes for Boston over 12 games last season. Far too many critics of the trade used the Celtics’ outstanding pre-trade record as evidence that the deal was a mistake without acknowledging that Perkins had essentially nothing to do with that record.

• The Celtics’ defense was outstanding all season and remained so in the playoffs. Defense is Perkins’ strength, obviously. If you’re looking for evidence that the team suffered in his absence, you have to find it here. And you can’t. The team’s defense put up stingy numbers when any of the core units were on the floor, save for those involving — you guessed it! – Green. (To be clear, Green didn’t play enough minutes to have a notable impact on the team’s overall defensive performance.) This is true for both Glen Davis, Boston’s crunch-time choice at “center” all season, and Jermaine O’Neal, who posted some of the best individual defensive numbers in the league last season.

• Perkins’ knee was not close to 100 percent, and he flailed badly in the postseason, particularly against Memphis in the Western Conference semifinals. He gave Nene fits in the first round, but he could not duplicate that against the Grizzlies, who happily ignored him when Oklahoma City had the ball. The Thunder scored 11 fewer points per 100 possessions during the playoffs with Perkins on the floor, and John Hollinger of ESPN.com detailed these problems at length during the series.

• Was a hobbled Perkins equipped to play effectively against the Heat, a team that was (at least at that point in the playoffs) comfortable using small lineups? It’s a counter-factual thing, but it’s not obvious Perkins would have been a huge help against that particular Heat team — especially given his health issues. It’s easy to say the Celtics needed someone to knock LeBron James and Dwyane Wade on their rear ends, but that alone wouldn’t have tipped the series Boston’s way.

Perkins has never been a plus offensive player, but in the past he could help by setting vicious screens, finishing the open looks he did get and making an acceptable percentage of his foul shots. In 2010-11 — and in that season alone — the negatives outweighed the positives, and it wasn’t close.

This is not an endorsement of the Perkins/Green trade. The stance here from the moment the deal happened was a mixture of understanding what Boston was going for and nervousness that it had targeted the wrong player (Green) to execute that plan. The Thunder will probably “win” the deal in the long haul, and Boston could get itself in trouble by overpaying Green. But it has long been time to move away from the idea that the Perkins swap was the most important factor in Boston’s failure to win the 2011 title. The deal may well have affected team chemistry, as Rondo seems to indicate, but the ability to magically heal Rondo’s dislocated left elbow (or perhaps Davis’ psyche) would have helped Boston’s chances in that particular series more than Perkins.