The NBA offseason can be a little hard to follow.

Quickly after a newly-crowned NBA champion hoists the Larry O'Brien trophy in mid-June, focus shifts to the league's draft and free agency period. Within a matter of only a few weeks, a lot of NBA rosters go through so many changes that they may seem unrecognizable by the end of the summer when compared to the previous year's iterations.

If you stop paying attention for just a few days, you can miss a lot. The big signings are rarely overlooked (hello, Kevin Durant!), but some of the smaller additions and subtractions fly far under the radar for all but the most obsessive NBA fans.

Because those signings -- the backup point guard, the veteran presence, the Plan B for an oft-injured starter -- can often be the real difference between a team improving or taking a step back in any given year, it can be an interesting exercise to take stock of the league as a whole once player movement has (more or less) ended.

Over the next few weeks, we will be rolling out articles just like this one, analyzing the changes within each division (and finish it all off with an all-encompassing summary at the end). The goal is for this series to serve as a helpful guide for catching up on the numerous changes that went on in the NBA this summer, while comparing how your favorite team's moves stack up against those made by the competition.

For the sake of comparison, we'll be using our proprietary metric, nERD.

If you're not familiar with nERD, 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).

In this study, we'll use last season's nERD scores for every player on the move, focusing on total nERD in and nERD out for each of the NBA's 30 teams.

Rookies and overseas imports have been left out of the calculations altogether because we have no idea how much (or how little) they'll contribute this year. These articles will focus solely on the movement of known commodities (so to speak) through trades and free agency, since they have nERD scores readily available that reflect their play during the 2015-16 NBA season.

Now, let's take a look at which teams got better in the Atlantic Division this offseason and which seem to have taken a step back.

Boston Celtics

nERD in: 5.2
nERD out: 0.4
Net nERD: 4.8

Al Horford was one of the biggest free agents available this summer, so he's a great get for a Boston Celtics team that finished tied for third in the Eastern Conference last year with a record of 48-34. Horford's nERD of 8.4 was the best of any player coming or going in the Atlantic Division this offseason, and the addition could push the Celtics up into the top slot among the best teams in the Eastern Conference, non-Cleveland Cavaliers edition. Throw in a top-three draft pick in Jaylen Brown and the Celtics should at least push for 50 wins and have a shot at the Atlantic Division crown after three straight seasons of the honor going to the Toronto Raptors.

Brooklyn Nets

nERD in: -9.4
nERD out: -16.3
Net nERD: 6.9

The Brooklyn Nets spent their offseason essentially swapping out a bunch of second- and third-string NBAers for new ones (six of one and half dozen of the other, as they say). Jeremy Lin might be an underrated pick-up, and Trevor Booker puts up some pretty decent per-36 numbers (10.2 points and 10.0 rebounds per 36 minutes last year), but there's not a whole lot else to be excited about here. To make matters worse, the Nets don't even have very many young prospects to get excited about because they have traded so many picks away over the last few years. Their Net nERD of 6.9 this offseason would be exciting if they didn't go 21-61 last season. Let's be honest, those seven or so wins added ain't dragging the Nets out of the gutter anytime soon.

New York Knicks

nERD in: -12.9
nERD out: -8.7
Net nERD: -4.2

If this were the 2011 offseason, the New York Knicks would probably be getting top marks for their incoming haul of Derrick Rose, Joakim Noah, Brandon Jennings, and Courtney Lee. Alas, it's 2016, and every one of those players is currently at a point in his career where he's putting up negative nERD scores and thus subtracting wins from his team. Derrick Rose, the centerpiece of New York's summer, registered one of the worst nERDs in the NBA last season at -8.4. The Knicks' trading for him qualifies as a splashy move for name recognition purposes (he was the 2011 NBA MVP, after all), but it's not likely to win them more basketball games. In fact, their offseason Net nERD of -4.2 suggests that all the moves they made will likely result in fewer W's in 2016-17.

Philadelphia 76ers

nERD in: -3.3
nERD out: -12.8
Net nERD: 9.5

It was a relatively quiet summer in Philly in terms of player movement. They added some veteran presence to their ridiculously young roster by bringing in Jerryd Bayless and Gerald Henderson, but those two signings aren't going to make the Philadelphia 76ers a playoff team overnight. Let's be honest, we're in what feels like year 10 of "the process" we're all supposed to be trusting, and the Sixers still stink. Their Net nERD of 9.5 is the highest in the division this offseason, but that's more a testament to how poorly the outgoing players rated last year while playing in such an efficiency blackhole than how savvy the team's moves were. At the end of the day, this Sixers' offseason will be defined by a bunch of unknown commodities: the franchise player they finally drafted (Ben Simmons), the guy who might finally be healthy (Joel Embiid), and the guy finally coming over from Europe (Dario Saric).

Toronto Raptors

nERD in: 1.6
nERD out: 3.1
Net nERD: -1.5

The defending division champs had a deafeningly quiet offseason outside the re-signing of their All-Star shooting guard, DeMar DeRozan. They essentially swapped out Luis Scola for Jared Sullinger at starting power forward, while watching backups Bismack Biyombo and James Johnson sign elsewhere. The departure of Biyombo will be felt the hardest, as his 4.4 nERD was the highest lost by any team in the division this summer, and that doesn't even account for the bonafide breakout he had during the Raptors' recent playoff run to the Eastern Conference Finals. The hope is that rookies Jakob Poeltl and Pascal Siakam can fill that void a bit, but losing Biyombo will almost surely result in a slight step back for the Raptors next season.

Conclusion

According to Net nERD, the Sixers and Nets had the best and second best offseasons in the Atlantic Division, respectively. Considering they placed last and second last in the Eastern Conference last year, though, it's hard to call a few wins added much of a step forward. Assuming the Knicks remain on the playoff bubble (their Net nERD suggests a major leap isn't imminent), crowning an offseason winner for the division would really come down to the two teams that made the playoffs last year: the Celtics and the Raptors. Since the Celtics added one of the top free agents (Al Horford, 8.4 nERD) and the Raptors lost one (Bismack Biyombo, 4.4 nERD), it's pretty easy to give Boston the nod.