A look at the eight first-round matchups:
No. 1 Miami Heat (66-16) vs. No. 8 Milwaukee Bucks (38-44)
Season series: Heat, 3-1.
Story line: The road toward what the Heat hope is a repeat championship finally gets under way, after a regular season that included a 27-game winning streak and the best record in the NBA.
Key Matchup: LeBron James vs. Everybody. The Bucks will have to send a bunch of different bodies and looks toward the reigning MVP in an effort to keep him guessing, and to get the Heat offense out of sorts.
X-Factor: Larry Sanders, only because he averaged one technical foul every 24 minutes against Miami this season, and he'll need to be on the floor if Milwaukee will succeed in its quest to at least slow Chris Bosh.
No. 2 New York Knicks (54-28) vs. No. 7 Boston Celtics (41-40)
Season series: Knicks, 3-1.
Story line: After ending the Celtics' five-year reign as Atlantic Division champions with their first division title since 1994, the Knicks will try to win a playoff series for the first time since 2000.
Key matchup: Tyson Chandler vs. Kevin Garnett. Neither center, both former Defensive Players of the Year, appeared in the final two meetings, and Garnett's absence was particularly noticed when the Knicks scored 100 or more in both games.
X-factor: Chris Copeland. The former pro player in Europe has become a surprising contributor in his rookie NBA season for the Knicks and seems to have found a place in the rotation.
No. 3 Indiana Pacers (49-32) vs. No. 6 Atlanta Hawks (44-38)
Season series: Tied, 2-2.
Story line: Neither team is exactly hitting the postseason in high gear, with the Pacers having lost five of their final six games and the Hawks going 11-15 since the start of March - then looking downright awful for the final two games, losses that at least got them out of the Miami side of the East bracket.
Key Matchup: David West vs. Josh Smith. Simply put, whichever guy plays better will probably see his team win the series.
X-Factor: Frank Vogel. The Indiana coach turned into a master motivator last season when Indiana ended up bowing to Miami in six games, though it was a series where the Pacers had the eventual champions down 2-1.
No. 4 Brooklyn Nets (49-33) vs. No. 5 Chicago Bulls (45-37).
Season series: Bulls, 3-1.
Story line: Ending a successful first season in Brooklyn with the franchise's first playoff appearance since 2007, the Nets open against the resilient Bulls, who made it to the middle of the Eastern Conference playoff standings even while playing all season without Derrick Rose.
Key matchup: Deron Williams vs. Kirk Hinrich and Nate Robinson - or Rose? Williams had a terrific second half of the season after treatment for his ankles around the All-Star break, though one of his poor performances during that span was a 4-for-12 night in a 96-85 loss at Chicago on March 2. Rose could still play, unlikely as it seems, after sitting out all season following major knee surgery.
X-factor: Reggie Evans. Evans had some decent scoring nights in the second half to go with his usual strong rebounding, but didn't manage a basket in three of the four games against Chicago.
No. 1 Oklahoma City Thunder (60-22) vs. No. 8 Houston Rockets (45-37)
Season series: Thunder, 2-1.
Story line: After combining for a blockbuster trade in the preseason that dealt James Harden to the Rockets, the teams meet in the first round as Oklahoma City tries to begin a second straight trip to the NBA Finals.
Key matchup: Thabo Sefolosha and Kevin Martin vs. Harden. Harden will try to outduel the player he used to replace in the lineup and the one who ultimately replaced him via trade.
X-factor: Patrick Beverley. The Rockets aren't afraid to give the backup point guard big minutes, and might need to use him if Russell Westbrook's quickness is too much for Jeremy Lin.
No. 2 San Antonio Spurs (58-24) vs. No. 7 Los Angeles Lakers (45-37).
Season series: Spurs, 2-1.
Story line: A top Western Conference rivalry in the last decade, this meeting comes without Kobe Bryant, who tore his Achilles' tendon last week.
Key matchup: Tim Duncan and Tiago Splitter vs. Pau Gasol and Dwight Howard. With Bryant gone and Steve Nash sidelined down the stretch, the Lakers reinvented themselves as an inside team, looking little like the usual Mike D'Antoni offense. Duncan, still near the top of his game as he turns 37 next week, and Splitter will have to control them while scoring themselves.
X-factor: Steve Blake. He started in Nash's place down the stretch and was particularly good after Bryant was lost, scoring 23 and 24 points in his final two games.
No. 3 Denver Nuggets (57-25) vs. No. 6 Golden State Warriors (47-35)
Season series: Nuggets, 3-1.
Story line: It's just the second trip to the playoffs for the Warriors in 19 years, which means Mark Jackson's team will have to guard against the just-happy-to-be-here pratfall that tends to affect clubs in that situation. Key Matchup: Ty Lawson vs. Stephen Curry. Lawson won't have to do it alone, but the safest way for Denver to grab control of this series would be to not allow Curry - the league's newly crowned single-season three-point record-holder - to shoot the Warriors into the second round.
X-Factor: David Lee. He's a two-time All-Star, an eight-year veteran and not only is this his first time in the NBA playoffs, but it's his first time playing for a team that won more than 36 games. That's right - his most recent postseason game was against Villanova.
No. 4 Los Angeles Clippers (56-26) vs. No. 5 Memphis Grizzlies (56-26)
Season series: Clippers, 3-1.
Story line: A pair of 56-win teams, both playing well and meeting a year after the Clippers went into Memphis and won a Game 7 to reach the second round of the playoffs - this has all the ingredients for a classic series.
Key Matchup: Blake Griffin vs. Zach Randolph. Griffin was bothered by back spasms in the season finale, and Randolph, who Heat forward Shane Battier affectionally compared to an ox earlier this season, will probably create a new bruise or two for the Clippers' star to deal with in this series.
X-Factor: Marc Gasol. A strong defensive player of the year candidate, he shot 52 percent in the series against the Clippers last season.