For the second straight season, the Miami Heat are on the verge of falling short of their goal of winning an NBA championship.

Miami lost to Boston 94-90 in Game 5 on Tuesday, as the Celtics took a 3-2 lead in the Eastern Conference Finals. Boston has a chance to close out the series at home on Friday and advance to the NBA Finals for the third time in five years.

The Heat were heavy favorites coming into the series, but the series has not played out that way. Boston has been the better team in this series, and was perhaps underestimated after struggling at different points in the playoffs.

The Heat are still favored to win the series with the Celtics up 3-2 and Game 6 being played in Boston on Thursday night. The Las Vegas Hilton Casino has the odds of Miami winning the title at plus 350, with Boston's chances at plus 450.

Other than a small hiccup against Indiana, Miami seemed to be on an unstoppable roll towards the finals. The Celtics, however, have slowed down the Heat, and pushed them to the brink of elimination.

Why haven't the Heat been able to breeze through this series as many people expected?

After three straight victories, the fact that the Celtics are simply a better team than the Heat seems to be abundantly clear.

Miami had a better regular season than Boston.

They finished second in the East with a 46-20 record, and won seven more games than Boston. Midway through the season, the Celtics were struggling mightily, and were almost out of the playoff picture. There was even speculation that they might trade some of their star players, like Paul Pierce or Ray Allen, and rebuild for the future.

Luckily, for Boston, they decided to stand pat and make another run for a championship.

Despite their struggles, Boston has proven to be one of the best teams in the NBA when healthy. Ray Allen and Rajon Rondo missed a combined 33 games during the regular season, and the shortened schedule seemed to have a negative effect on the team.

Now that the Celtics have a day of rest in between every game, they are able to play to their full capabilities.

LeBron James and Dwyane Wade are better than anyone on the Celtics, but Boston has a tremendous advantage after that. The Celtics probably have five of the best eight players in this series when Chris Bosh is healthy, and James and Wade are showing that they can't overcome such a disparity in talent.

The injury to Chris Bosh has certainly hurt Miami, but even with him on the court in Game 5, the Heat struggled. He had a plus-minus rating of minus 12 on Tuesday night.

The Heat aren't even having trouble because James and Wade are playing poorly.

Unlike in last year's NBA Playoffs, LeBron James is not at the top of the list of reasons why the Heat might not win it all. James has been outstanding in this series, averaging 31.8 points, 10 rebounds, and four assists on 50 percent shooting per contest.

In the NBA Finals a year ago, James' play suffered. He averaged less than 18 points per game in the series against the Mavericks.

Wade has had his struggles, but he's played about as well as can be expected against the Celtics. He's averaging 22 points, 5.2 boards, 4.8 assists and two blocks in five games against Boston.

Even with their two stars doing what they are supposed to do, the Heat still look like the worse team.

The Heat just don't have the supporting cast to match up with the Celtics. Players like Shane Battier and Mike Miller are past their prime, and Miami relies on them to play major minutes. Often times, the Heat need James or Wade to score close to 40 point in order to win against the best teams in the league.

That's too much to ask, even for players of their caliber.

Often times when Miami can't come up with a victory, either James or Wade gets the brunt of the blame. They won't deserve it this time.

If that's the case, maybe a Celtics victory shouldn't be viewed as an upset.