On December 16, the Boston Celtics beat the Charlotte Bobcats 106–100 in Charlotte. The win was Boston’s fifth straight, with four of them coming on the road, and put them into first place in the Atlantic Division at 10–13. Boston was young, had a superstar centerpiece in Paul Pierce, and a winnable division for the taking. It appeared team president Danny Ainge’s rebuilding plan might be about to bear fruit.

Unbeknownst to the Celtics, it was the last good news they’d have for some time. Wally Szczerbiak tweaked an ankle that day, and one game later Pierce was diagnosed with a stress reaction in his left foot that shelved him for two months. Just in case that didn’t ruin Boston’s season, three weeks later the rapidly emerging Tony Allen tried to dunk after the whistle and blew out his knee upon landing. More injuries followed, while Boston’s youth and inexperience proved more of a liability as the year went on.

In the two months since, they’ve won twice. You read that correctly — twice. Boston is 2–25 in its past 27 games, including defeats in the past 18 in a row. The Celtics are threatening the NBA’s all-time mark of 23 consecutive losses set by the Vancouver Grizzlies in 1995–96 and tied by the Nuggets in 1997–98.

Even though Pierce is back in the lineup, Boston has a decent chance of breaking the mark. The Celtics have a very winnable game at home against Milwaukee on Wednesday — the Bucks are 3–15 since their own unfortunate afterthe-whistle knee injury, to star guard Michael Redd. But if the Celtics falter against Milwaukee, they might as well plan the record-breaking ceremony. Boston’s next five games are on a trip out West, a land where even the best Eastern teams don’t win more than a game or two.

Whether Boston breaks the mark or not, it’s jarring that a team that appeared so respectable for a quarter of the season could overnight turn into a laughingstock. How did this happen?

Part of the answer is that the Celtics have been snakebit, even after considering the injuries. For instance, Boston lost Sunday night on a buzzer-beating shot by Minnesota’s Ricky Davis, one that was doubly painful because they traded Davis at midseason a year ago. It was the fifth loss in the streak that came by five points or less.

But the more telling number in Boston’s streak is the lack of onesided defeats. Normally a team that suffers through such a brutally bad streak would suffer several laughers — Vancouver lost three times by 25 or more during its steak, for example, while Denver had five defeats by greater than 20.

But the Celtics have been in nearly every game, not dropping a single contest by more than 14 points. In fact, they only have two losses by 20 or more the entire season (defending champion Miami, by way of contrast, has lost eight times by that margin).

The upshot is that the Celtics are quite a bit better than their 12–40 record indicates, which becomes clear once one looks at Boston’s point differential. As I’ve mentioned before, there is a highly predictable relationship between points scored, points allowed, and how many games a team wins. Clubs can deviate from that pattern over short periods of time, and sometimes over a full season. But no team — regardless of its “clutch” reputation — has been able to escape this inalienable law over a period of years.

The “Pythagorean 16.5 method” describes this relationship — take the team’s points scored to the 16.5 power, divide by the sum of points scored and points allowed to the 16.5 power, and you have an expected winning percentage for the team. Based on that method, Boston should be 17–33 right now, which is a nice way of saying bad luck has cost the Celtics five games in the standings. Boston’s Pythagorean record is better than that of six other teams, in fact.

This is important because of its implications for the future. Much like the Nets, the Celtics face a very difficult decision in the coming days leading up to the trade deadline about whether or not to trade their star players. If Boston decides it’s time to break out the dynamite, then it makes sense to trade Pierce while his value is highest, and try to find homes for veterans like Szczerbiak as well.

In the absence of other information, looking at Boston’s win-loss record might incline the Celtics to do just that. But looking at their Pythagorean mark, which is the more valid indicator going forward, I think that would be the wrong move.

The Celtics could be quite a bit better a year from now. In addition to three recuperated stars in Pierce, Szczerbiak, and Allen, Boston is going to get a very high draft pick as the result of its misfortune. And this is a great year for such a thing to happen because the draft is projected to be the best since the LeBron-Melo-Wade-Bosh class of 2003 (though locals know it more fondly as the Sweetney-Planinic-Lampe-Vranes draft).

So the right move may be the counterintuitive one — to deal youth for experience. Boston has spent the past few years hoarding young talented players and now has more than it knows what to do with. Players like Al Jefferson, Delonte West, Rajan Rondo, Sebastian Telfair, Kendrick Perkins, and Gerald Green all are under 25 and have great appeal to rebuilding teams.

Thus, the Celtics could parlay those players into another starcaliber performer to play alongside Pierce, most obviously at point guard. I’m not suggesting Boston trade all of them, but parlaying two or three into another quality regular could radically change the team’s outlook heading into next season. Throw in a midlevel exception, a high draft pick, and a return to health from their best players, and the outlook brightens considerably.

So if the Celtics do break the futility record next week, file this nugget away in the back of your head. This team isn’t nearly as miserable as the two clubs whose record it may break, and with a few deft moves it could be back to health much faster than you might think.

jhollinger@nysun.com