The NBA offseason can be a bit of a blur. The draft happens shortly after the NBA Finals, and free agency opens up just a few days after that. Less than a month after the Larry O'Brien trophy gets handed out (props, Golden State), a lot of teams have rosters that are practically unrecognizable from the year before.

Stop paying attention for just a day or two, and you can look at any team's roster by the end of July and realize that it's filled with rookies you might not know, players acquired in trades you forgot happened on draft night or shortly after, and free agents who you didn't realize signed in the place that they had signed (or who ended up signing with their original team instead of Dallas, let's say).

If you went off the grid for a couple weeks for a vacation (like yours truly), it might take some time to wade through all the player movement updates and to get a sense of what each team actually managed to accomplish through all those transactions. Over the next few weeks, we hope to give you a way to catch up on all the changes with this series of articles on each division.

For analysis purposes, there are a number of factors and nuances that you could consider to predict which teams will get better and which ones will get worse. You could look at roles, try to guess rotations, take a stab at which rookies will hit and which ones won't, analyze aging curves, etc; but any conclusion you would draw from that would purely be conjecture, since none of us really knows how next season is going to pan out after all these changes.

In which case, for the sake of relative simplicity, we're going to do a team-by-team analysis (divided by divisions) and look solely at their nERD in and nERD out.

If you're not familiar with our in-house nERD metric, it combines several offensive, defensive, and usage factors to produce one number that is meant to project a player's overall value to his team. That final number is an estimate of how many games above or below .500 a league-average team would win over an 82-game season with the player in question as one of its starters. It's comparable to Win Shares, but is meant to be predictive (projecting an 82-game season) as opposed to descriptive (how many wins the player has contributed to his team in the past). For the sake of this study, we'll use last season's nERD scores.

Also, rookies have been left out altogether, since we have no idea how much (or how little) they'll contribute in their rookie seasons. These articles will focus solely on the movement of known commodities (so to speak) through trades and free agency.

Without further ado, let's look at which teams got better and which look to have dropped off in the Atlantic Division so far this summer.

Boston Celtics

nERD in: 2.8
nERD out: 0.9
Net nERD: 1.9

The Celtics had a relatively quiet offseason, but managed to corner the market on decent-ish frontcourt players. They traded for former All-Star and recent champion David Lee. Now, he and fellow newcomer Amir Johnson will fight for frontcourt minutes with Jared Sullinger, Tyler Zeller, Kelly Olynyk, and Jonas Jerebko. After finishing as the East's 7 seed last season, Boston has secured that as their relative ceiling for next year with the mere 1.9 nERD added.

Brooklyn Nets

nERD in: -11.3
nERD out: -6.0
Net nERD: -5.3

The Nets shed some of their monstrous salary bill by buying out Deron Williams and stretching his remaining $27.5 million over the next five years. D-Will's -1.8 nERD last season suggest his productive days are mostly behind him anyway, but it's not like the Nets made a splash in free agency to make their team any better without him. A few castoffs from last year's Knicks, Lakers, and Sixers ended up being all Brooklyn could attract/afford and the -11.3 nERD they brought in was easily the worst mark in the Atlantic, as was the -5.3 Net nERD. The Nets are likely in for another sub-.500 season, but at least now they won't have the payroll to make people think they should be better.

New York Knicks

nERD in: -3.4
nERD out: -16.8
Net nERD: 13.4

The New York Knicks have been the butt of many jokes over the last few years, but they quietly had one of the better offseasons in the Association, mostly through addition by subtraction. Their 13.4 Net nERD was the best in the Atlantic, simply as a product of shedding -16.8 nERD in the players they traded away or let walk in free agency. That's not to say that the Knicks will be contenders next season by any stretch of the imagination -- since they still have to fill out their roster with unsigned rookies and leftover free agents that will likely all contribute subzero nERDs -- but they've done a decent job of washing off the stink of last year's 17-65 team, while bringing in pedigree (Robin Lopez and Arron Afflalo) and upside (Kyle O'Quinn and Derrick Williams).

Philadelphia 76ers

nERD in: -6.0
nERD out: -6.3
Net nERD: 0.3

The Sixers got rid of some inconsequential players and brought in some other ones. They drafted another high-upside big in Jahill Okafor (that's good), but have lost Joel Embiid for another season due to injury (that's bad). Death, taxes, and another season of Sam Hinkie's tank job Sixers finishing last or close to it. Nothing more to see here.

Toronto Raptors

nERD in: 13.6
nERD out: 7.5
Net nERD: 6.1

The Toronto Raptors have won back-to-back Atlantic Division titles and it's hard to imagine that they won't win their third in a row. All four players they added this offseason through free agency finished last year with a positive nERD, suggesting that Raptors GM Masai Ujiri is perhaps a numberFire subscriber. They lost some nERDy players as well, but the Net nERD of 6.1 suggests Toronto will field an even better team than last year's 49-33 squad; especially when you consider the players in are mostly known for their defense -- an area in which last year's Raptors team ranked 25th in the NBA and clearly needed to improve in this offseason.

Conclusion

Since the Knicks still have some roster tinkering to do (that will almost definitely drag their inflated Net nERD down) and the Raptors added only players with positive nERDs -- including the nERDiest player added in the whole division in DeMarre Carroll (29th in the NBA last season with a nERD of 5.8) -- it's probably safe to say that Toronto had the best offseason of any team in the Atlantic Division. Their 13.6 nERD added not only paced the division, but also represented one of the greatest gains in the whole NBA.