Everybody's favorite three this season.

Someday we will stop discussing Ray Allen’s departure from the Celtics (probably when actual games start and we have real data to analyze), but until then, his absence creates a series of complicated and interesting changes for the upcoming season that deserve examination.

Ask any casual fan what Allen brings to a team, and the easy (and correct) answer is three point shooting. So for Boston, one of the best long range shooting teams in the NBA in 2011-2012 (7^th overall, .367), losing a player who shot .453 from behind the arc will certainly change their offense. How much will it change? Considering Boston’s other personnel changes, the answer is likely “quite a bit.”

First, by way of establishing a baseline for 3-point shooting, here’s former Stetson University (a Division 1 NCAA school in the Atlantic Sun conference) head coach Glen Wilkes:

“As a coach analyzes how much he will shoot the 3-point shot, he should keep the following statistic in mind: 33% shooting from 3-point range is the same as 50% shooting from 2-point range…

It is extremely important to determine early in the practice season just who will be allowed to take the 3-point shot…

A word of caution. Most of your players will think they are 3 point shooters…You must demand that they avoid practicing the shot if they are not going to be given the opportunity to shoot it in a game.”

The veracity of the first statement can be confirmed by simple math: 33% shooting from 3-point range is indeed equal to 50% from 2-point range, and therefore efficient enough to be worthwhile. At .367, the Celtics shot an appropriate percentage from behind the arc last year, although perhaps they should have attempted more shots from that range, since they were 24th in 3-pointers attempted and 25th in adjusted offensive ratings (points per possession, adjusted to the strength of the defense). Part of the reason Boston was so low in 3-point field goals attempted was their slow pace, of course: the Celtics were 21st in the league in pace.

Another reason the Celtics took so few 3-pointers is because, quite frankly, they didn’t have very many shooters to take them. Ray Allen and Paul Pierce were the only consistent shooters from deep on the team. Of all the players on the team who took 60 3-pointers or more, only Pierce, Allen, and Mickael Pietrus shot over .333.

Boston’s three point shooting went from limited to horrifying in the playoffs. Only one player shot over .333, Keyon Dooling at .396, who also only took 28 attempts. Everyone else was abysmal, particularly Mickael Pietrus, who shot just .222 from behind the arc in the postseason.

So while the Celtics were well above the minimum level of efficiency during the regular season, they were mostly dragged there kicking and screaming by Ray Allen. Here is where the quandary begins: without Allen’s .453 FG%, the Celtics’ 3 point percentage falls to .338, still above the minimum efficiency rate, but barely. At .338, the Celtics would have been just below the Mavericks (.339), who were 19th in the NBA. Related: the Mavericks were 4th in 3-pointers attempted and 22nd in offensive efficiency. Not good company for the C’s to be keeping.

There is, however, good news: nearly all of Boston’s offseason acquisitions should help improve Boston’s 3-point percentage. Here’s how Boston’s roster of 3-point shooters currently shapes up, all stats from last season.

Some (probably unnecessary) observations:

• Jason Terry takes a LOT of threes, which is a good thing, given his percentages. However, it can be easy for wing players to get used to floating around the perimeter instead of creating opportunities for themselves. Boston already has players who can float around the three point line; they will need Terry to do more on offense. And there’s no reason to believe he won’t: last year, 3-pointers made up 43% of his shots, which is very acceptable.
• Though percentage-wise, Rondo probably shouldn’t be shooting threes, his attempts are likely to be more beneficial than Jeff Green’s, even though Green’s numbers are better. Rondo’s three point attempts help keep the defense honest. Green’s 3PAs indicate that the defense has been doing a good job of taking away better looks. It should also be noted that Green’s numbers are from 2010-2011, and that when he was with OKC, he shot .303, a better percentage, though still well below the minimum.
• Bradley’s extremely high 3-point percentage is a result of taking smart threes within the offense, mostly from the corner. When shooting from the corner last season, Bradley hit 56%. From above the break, Bradley shot just 2-18, for 11%.
• If we take out Rondo’s and Green’s attempts from the chart above, Boston’s percentage balloons to .377, .010 higher than last season when Allen was bombing away. If Doc is smart (and, obviously, he is very, very smart), he will tell Jeff Green to stay the hell off the three point line, and Rondo to only take 3-pointers late in the shot clock, or when the defense is sagging unnecessarily far. This is basically Rondo’s modus operandi anyway, so that shouldn’t be a problem.
• These numbers, of course, don’t take into account Dionte Christmas, who is yet to play a regular season NBA game.

For the sake of comparison, here are Miami’s numbers/3-point shooters as well, since essentially everything about Boston’s offseason has been geared toward beating them.

Some more thoughts:

• If every player on Miami shot exactly the same numbers this year, the Heat would have a considerably lower team 3-point percentage than Boston, at .356, even with the addition of Ray Allen.
• Holy hell, Mike Miller. Injuries and all, Miller shot the exact same percentage as Allen, though admittedly, he took over 100 fewer attempts than Allen.
• Despite Shane Battier’s absolutely torrid playoff run from behind the arc, he was still BARELY over the minimum efficiency rate. Moral of the story, I suppose, is don’t leave him TOO open while you are busy guarding everyone else.
• The good news: Wade is a bad three point shooter. The bad news: he took roughly 150 fewer 3-point attempts last year, so he seems to be more self-aware than previous years. Damn everything.
• The bad news: LeBron James is efficient when he is shooting 3-pointers. I don’t have any good news to balance that out. LeBron was not elite, but efficient enough. Given everything else he’s good at, merely being efficient from three point range is downright terrifying.

To make a long story slightly shorter, the Celtics should be a good 3-point shooting team next season, and they could even improve on last year, as long as they establish the correct players taking the correct shots. Obviously, having Allen would have been ideal, but they don’t need his contributions to be very good from beyond the arc.

The biggest question, then, is how many threes will the Celtics attempt? This is hard to project, but considering that there will be more offensive weapons this year, and most of the new additions are three point shooters, Boston should move up from 24th in 3PAs. As long as this doesn’t take good shots away from supremely efficient offensive weapons like Kevin Garnett, more threes for the Celtics could be a very good thing.

Follow Tom on Twitter: @Tom_NBA