NBA Eastern Conference Finals Preview: Celtics vs. Cavaliers

It's not often LeBron James is an underdog.

It might not even be the case, even with the Cleveland Cavaliers second to the Boston Celtics in the Eastern Conference, but by the letter of the law, the reigning champions aren't the favorites to advance to the NBA Finals.

Boston overcame a tough series -- two, really -- after besting the Washington Wizards in seven games in the semifinals. Just two days later, they'll host the Cavs in Game 1 in attempt to reach the NBA Finals merely a few years after blowing up the whole roster.

What all should we know?

Boston Celtics (1)

Record: 53-29
nERD: 57.1
Championship Odds: 9.7%

Cleveland Cavaliers (2)

Record: 51-31
nERD: 59.0
Championship Odds: 11.8%

Regular Season Series - Cavaliers 3, Celtics 1

The Cavs took three of four from Boston in the regular season. In those four games, the Cavaliers outpaced the Celtics in terms of net rating by 5.9 points per 100 possessions.

The first matchup came way back in early November, a 128-122 home win for the Cavaliers. Cleveland shot 57.1% in terms of effective field goal percentage, compared to 53.6% for Boston. The Cavaliers made 0.381 free throws per field goal attempt, compared to just 0.198 for Boston. On the full season, the Cavaliers were 19th by this measure (0.206), and the Celtics were 8th (0.220).

Jae Crowder, Al Horford, and Kelly Olynyk all missed that game.

The second matchup, December 29th, was a 124-118 win in Cleveland again for the Cavaliers. The Celtics shot 57.6% in terms of effective field goal percentage, but the Cavs bested them at 60.1%. Cleveland again held the free throws per field goal attempt edge (0.289 to 0.235), and they grabbed 36.1% of available offensive rebounds, compared to 15.4% for Boston.

Boston outshot Cleveland 54.5% to 46.2% in their third matchup, March 1st, the lone win for Boston in this series (103-99). The Celtics narrowed the offensive rebounding gap but still were outdone (23.5% to 21.6%). James triple-doubled (28 points, 13 rebounds, 10 assists), but Isaiah Thomas' 31 points, Horford's near triple-double (9 points, 10 rebounds, 10 assists), and Crowder's double-double (17 points and 10 rebounds) were too much.

Kevin Love and J.R. Smith missed that game.

The final game of the series came April 5th, and Cleveland was without Tristan Thompson, a rare phrase to read. They still won 114-91 and collected 30.2% of available offensive rebounds, compared to 17.4% for Boston. All five Boston starters had a plus/minus of at least -10, and James was a plus-32. Boston shot just 21.2% from three-point range and 62.1% from the free throw line. Cleveland shot 30.6% and 94.4%, respectively.

How the Celtics Can Win

Boston needs to rebound on both sides of the floor.

Horford has increased his rebounding rate from 11.8% in the regular season to 12.7% in the postseason, but it's not enough by itself. Boston is last in the playoffs in rebounding rate at 45.7% and hauled in just 45.9% of rebounds against the Cavaliers in their regular season series.

The Cavaliers ranked second in the regular season in effective field goal percentage (54.7%), so limiting extra chances is crucial.

Celtics Player to Watch - Al Horford

Another key is just getting big-time scoring from Thomas, which could be asking a lot even against this weak Cleveland defense if they decide to trap him and force him to make plays rather than get to the rim.

Make no mistake: Boston can't win if Thomas isn't amazing. That might sound harsh, but it really seems true. The problem is that the Cavaliers can outlast great play from Thomas, who averaged 29.5 points and 6.5 assists against Cleveland this season. I'd be floored if Cleveland's game plan wasn't to take away Thomas.

That's why it's probably on Horford to maintain his excellent postseason play. Horford has shot 58.3% from three-point range, en route to a 71.8% effective field goal percentage. He's also averaging 16.1 points, 7.5 boards, and 5.8 assists per game.

Horford at times could be forced to be the primary playmaker if Cleveland can take Thomas out of the game, and how Horford balances his hot three-point shooting and cleaning the glass could sway the series significantly.

How the Cavaliers Can Win

Find the hot shooters. Really, we could simply say they need to dominate the boards, but they should do that by default until Boston changes their approach.

What it really might come down to is finding which guys are shooting well in a particular game. The Cavaliers have eight players who have attempted at least 10 three-pointers in the playoffs. Nine of them are shooting at least 40.0% from beyond the arc.

Only Kyrie Irving (28.1% on 57 attempts) is below that mark. Irving shot 44.0% in the playoffs last season from deep and 40.1% in the regular season.

With James running the offense and the right shooters around him, the Cleveland offense should have an advantage either on the perimeter with these shooters or at the rim (Boston was just league-average at defending shots within three feet of the rim this season) if the spacing and shooting approach goes like it has in the playoffs so far.

Cavaliers Player to Watch - LeBron James

It's LeBron. It's gotta be LeBron.

The Cavaliers played 33 minutes without James against Boston this season. They had an offensive rating of 82.6 and a defensive rating 104.7, for a net rating of -22.1. The Cavs had sub-zero net ratings with just two other players off the floor: Love (-3.6) and Smith (-2.6).

Cleveland won't have too many minutes without James on the floor -- he's played 88% of the possible minutes this postseason, despite the Cavs winning their eight games by 9.6 points on average -- and they can't afford to have him sit.

How well James holds up will really dictate how well the Cavaliers play.

Series Prediction

Boston is a good team, not a great team. The Cavaliers are a good team, not a great one, either. Boston had a regular season net rating of 3.1, seventh on the season. Cleveland's 2.9 was eighth. Yet they've made it to the NBA's final four.

Both sides have issues, and the Celtics have been pushed to brink by the Wizards already and to six games by the Chicago Bulls.

The Cavs are the reigning champions and have one of the best players in the world (he still is; I'm just being diplomatic). And it's safe to say that they've overcome their weaknesses so far in the playoffs.

According to our algorithms: Cavaliers are 51.49% favorites.

My final prediction: Cavaliers in five.