All season, one of the most fascinating NBA debates has been who will come out of the East? The Milwaukee Bucks have the league's best record and net rating, but maybe the Boston Celtics can get their collective act together at the right time. Maybe the Toronto Raptors, with Kawhi Leonard, are finally poised to break through. Maybe the Philadelphia 76ers, with Jimmy Butler alongside their two young stars, have enough firepower. After Thursday's trade deadline, this debate is even more interesting, and the particulars have changed drastically. 

All four contenders -- with apologies to the lovable Indiana Pacers, who were in this conversation before the Victor Oladipo injury -- have reasons to be happy. Let's check in on each of them.

Milwaukee adds another piece

It is almost unfair how well Nikola Mirotic fits Mike Budenholzer's system. He is going to have a green light to shoot as many 3s as he wants, and he is going to give Giannis Antetokounmpo even more space to operate. The Bucks didn't have to do anything before the deadline, but they recognized that Mirotic would be a significant upgrade over Ersan Ilyasova, and they might even be able to get away with playing him and Antetokounmpo at the 4 and 5 if Brook Lopez is exploited defensively in the playoffs. 

It is possible that general manager Jon Horst, a complete unknown to the average NBA fan, will win Executive of the Year. The Lopez signing was the biggest bargain of the summer, and now his front office has basically turned Thon Maker into an above-average stretch 4, who plays decent defense, too. The cost was four second-round draft picks, a fair price to pay for significantly increasing Milwaukee's chances of getting out of the East. Before this deal, the Bucks' offense was already terrifying -- they scored 50 points in a quarter on Wednesday. They will be even harder to stop now. 

Raptors now tougher, smarter

In another ideal marriage between player and system, Marc Gasol will soon be facilitating offense under Nick Nurse. The Raptors, hoping to maximize the only season they've been promised with Kawhi Leonard, upgraded from the solid Jonas Valanciunas to a center who knows how to make everyone around him better. As long as Gasol is healthy, he is a significant upgrade, both in terms of skills and how he reads the game. In order to make this happen, Toronto sacrificed guard Delon Wright, who is headed into restricted free agency, and wing C.J. Miles, who had lost his spot in its crowded rotation. 

The move likely pushes Serge Ibaka to the bench, but it will be interesting to see how the frontcourt playing time get divided. Despite his resume, Gasol might have to live with his minutes getting reduced against, say, Al Horford. He will help the Raptors deal with Joel Embiid, though, and Gasol, who has taken more than four 3s a game over the past couple of seasons, has the ability to space the floor more effectively than Valanciunas did. He is the rare player who makes any team he is on tougher and smarter. 

Sixers get busy

General manager Elton Brand turned Philly's Big 3 into a Big 4 by acquiring Tobias Harris, a bold move not only because of the inherent chemistry concerns, but because of the high price his front office paid. The Sixers no longer have their 2020 first-round pick, Miami's 2021 first-round pick or guard Landry Shamet, who was a steal in last year's draft and seemed like JJ Redick insurance. They've also made sweeping changes to their supporting cast -- welcome, Boban Marjanovic, Mike Scott, Jonathon Simmons and James Ennis -- and the depressing Markelle Fultz saga is finally over (for them).

Fultz was supposed to be the perfect complement to Ben Simmons and Embiid. He was supposed to defend multiple positions, make plays and space the floor. He was supposed to be a star. Philadelphia has wildly pivoted from its patient plan to build around three elite young players, and now there is all sorts of pressure to succeed in the short term. I truly don't know whether or not this new Sixers team will be more than the sum of its parts, but I do know that their starting five looks formidable. Can't wait to watch them.

No news is good news in Boston

The best thing that happened to the Celtics had nothing (directly) to do with them: Anthony Davis didn't get traded. Boston has been planning to go after Davis for years, but, thanks to a weird CBA quirk, needed to wait until the summer. If the New Orleans Pelicans had dealt him to the Los Angeles Lakers or elsewhere, the front office's dreams would have been dashed. The Kyrie Irving situation still seems a bit weird, but the Celtics still have the talent to compete for a championship this season and present the Pelicans with a trade package headlined by Jayson Tatum afterward. 

Boston made one minor move on Thursday, waiving guard Jabari Bird to create a roster spot. This could wind up being significant, depending on who ends up getting waived. Wesley Matthews is reportedly on his way to Indiana, and the Celtics probably might not be able to offer as big a role as their competitors, but this puts them in the game if they need to be. (One competitor to watch: The Raptors, who have five open roster spots after dumping Malachi Richardson and Greg Monroe.) This is small stuff, though -- what matters is that they could be much better next season.