by Leo Sepkowitz | @LeoSepkowitz

Last season, only two teams managed first-round upsets—the Clippers (a 5-seed) and Sixers (thanks to Derrick Rose blowing out his ACL). This season might be more unpredictable. The West is strong one-through-eight, so each team has a puncher’s chance to advance out of the first round. The East is a little less fun, but should feature at least two very competitive series.

Each underdog has strengths that could lead to them upsetting a higher-seeded team. I call these “Swing Factors.” Swing Factors aren’t things like, “If the White Mamba Scalabrine returns for Boston and averages 25 per game and plays lockdown D on Melo, Boston might win their series.” Instead, they’re based on things that teams or players were actually able to do during the regular season, even if it was only for short stretches. There’s one Swing Factor per series.

Eastern Conference

MATCHUP: (1) HEAT VS (8) BUCKS
Swing Factor: Overcoming The BBIT
Chance of Upset: 1%

For Milwaukee to have a prayer at making this an interesting series, they’ll need to disprove my Bucks Backcourt Incompatibility Theory, or BBIT. Throughout the year, Ellis and Jennings have been totally unable to play off of each other. When one plays well, the other one plays terribly. Here’s the proof:

This year, Jennings scored 30 or more points 10 times. In those games, Ellis averaged 16.2 points on just 39 percent shooting. Much worse, in nine 30+ Ellis games, Jennings made roughly 26 percent of his shots for 9.9 points per game. Yikes. The Bucks have two offensively gifted guards, but they don’t have a clue how to play together.

I wanted to stay away from “ifs” in this piece, but this one is too good to pass up. So yes, I’m breaking my only rule on the very first matchup.

If the BBIT (pronounced “bit” for when you’re using it to impress women) is proved incorrect, it’ll open the door for Milwaukee’s secret advantage to take over…

Here’s a stat neither of us knew until I googled it: only Denver is better than Milwaukee on the offensive glass.

Here’s another one (much more guessable): Milwaukee blocked more shots than any team not located in Oklahoma City this year. About 40 percent of those stuffs came courtesy of rejection maestro Larry Sanders. But Sam Dalembert and Ekpe Udoh blocked more than a shot per game, giving the Bucks serious depth in the paint.

With those three plus Ersan Ilyasova (7.1 rpg) helping on the glass and Luc Richard Mbah a Moute playing strong perimeter D, the Bucks have an outside shot to defend home court advantage, or at least play a nail biter or two in Milwaukee.

But frontcourt production won’t matter if their “star” backcourt can’t figure out how to co-exist.

MATCHUP: (2) KNICKS VS (7) CELTICS
Swing Factor: Jeff Green’s Reliability
Chance of Upset: 15%

Two years ago, the Cs and Knicks met up in the first round after a 56-win season by Boston and a 42-win campaign by New York. Boston swept the series. This time around, it’s the Knicks that sit among the East’s elite while the Celtics floated around .500 all year. In the words of the great Michael Scott, “Well, well, well—how the turntables…”

Jeff Green was comically inconsistent this year. He scored just 10 points before his March 18 43-point show, and followed it with totals of 13, 10 and 12 points in Boston’s next three. In February, he sandwiched a 31-point performance against Phoenix with 15- and 11-point games. In all, he scored 5 points or fewer a whopping 13 times this year. That is way too many for a third option on a Playoff team.

He’s gotten better every month since January, and averaged over 17 points (48 percent) and 5 boards after the All-Star break. Boston may be without Rajon Rondo, but they’re not toast yet. Paul Pierce always shows up in the Playoffs and KG turns up the heat in big games. But to get past the Knicks, the Celtics will need Green to flip on the switch and keep it on.

MATCHUP: (3) PACERS VS (6) HAWKS
Swing Factor: Atlanta’s Three-Point Shooting
Chance of Upset: 15%

The Hawks quietly hit the fifth-most threes in the League this year. Only Stephen Curry, Klay Thompson (sweet backcourt) and Ryan Anderson hit more treys than Kyle Korver. DeShawn Stevenson, Devin Harris and Jeff Teague all hit at least one per game, and Josh Smith knocked one down every other game. Equally important, they had the sixth-best three-point percentage in the League.

Their two best players are their big men, Smith and Al Horford, but Atlanta can rain from deep. Here’s the bad news: Indiana was the best team in the League against the three-ball…by far. Opponents hit shy of 32.6 percent of their threes this year—next best is 33.9. The Hawks are going to have a tough time getting good looks from downtown, and Roy Hibbert should be able to contain Horford. This is a terrible matchup for Atlanta.

One note about the Hawks (kinda): What does it say about Joe Johnson that Atlanta slid down just one spot in the standings after dumping him for DeShawn Stevenson (eh), Jordan Williams (eh), Jordan Farmar (playing in Turkey), Anthony Morrow (dealt away) and Johan Petro (don’t get me started)?

MATCHUP: (4) NETS VS (5) BULLS
Swing Factor: Mental Toughness
Chance of Upset: 30%

Thirty-two of the Nets’ 49 wins came against sub-.500 teams this year. I think that number summarizes who they are. Brooklyn has great talent. Brook Lopez and Deron Williams are All-Stars. Joe Johnson is pretty good, Gerald Wallace is still a plus wing defender and Reggie Evans might win MVP after his ridiculous final 22 games: 6.5 points, 16 boards per game. But I’m not sure how tough they are.

Johnson’s made big shots late in games this year (14 points, 4-4 FG) in games within three points with 10 seconds or less remaining). But in close games with a few minutes left, Brooklyn starts to tighten up. Sometimes Lopez completely disappears (coach PJ Carlesimo has frequently played Andray Blatche at the end of games) or forces shots. Williams and Johnson end up in isolations, not really using the other one to get an open look. Basically, the Nets look nervous late in games.

The two teams faced off four times this year. In Game 1, Brooklyn led by four with two minutes left and lost by one. In Game 2, the Nets held off a late comeback by the Bulls who were without Carlos Boozer and Joakim Noah. Chicago won Game 3 easily. Game 4 saw the Nets blow an 11-point halftime lead. They led by three with 52 seconds left and got outscored 5-0 from there…at home.

When a game enters crunch time, the Bulls tend to play well. When games were within five points with five minutes or less remaining, Chicago had the fifth-best points differential in the NBA this year.

With a great front line, which now features breakout star Jimmy Butler, too, they can control the glass and get easy buckets despite lacking a typical go-to guy. But it looks like they’ll be without Joakim Noah for at least one game, which would be a huge blow to the Bulls’ hopes. I originally had the Bulls’ chances at 40 percent (they’re about even except for Brooklyn’s home-court advantage), but bumped that down after recent reports on Joakim’s foot weren’t promising. Too bad they didn’t keep Omer Asik…

Side note: Obviously Derrick Rose returning for this series would be the ultimate Swing Factor, but it doesn’t seem like it’s going to happen.