It's not about how you start, but how you finish.
There's no better way of describing sports than with that statement. If an NBA team starts out the year with an impressive record but begins to simmer down near the start of the postseason, they're much less likely to win a championship over the team that had an average year but got really hot at the end of the season.
It's happened to so many teams over the years. The Memphis Grizzlies last year rode some momentum at the end of the season and came within a game of the Conference Finals, the Boston Celtics in 2010 won a few games at the end of the year and made it to the NBA Finals and even the Super Bowl champion New York Giants won a lot of games at the end of the year just to make it into the playoffs.
It didn't matter if they were 9-7 and going against teams with significantly better records. All that mattered was that they were riding momentum and were going to surf that wave until otherwise. You'd be surprised what a little bit of momentum could do for a team that pretty much played .500 basketball for the entire year except the end.
Take a look at the San Antonio Spurs last year. They started out the season 35-3, but then proceeded to play .500 ball the rest of the year before losing in the first round. Don't you think that they would have been a lot better had they played .500 basketball for the first half of the year and then finish the year winning 35 of their next 38?
Of course they would have. That's what momentum and having a winning mindset can do for you. In fact, these five teams are the ones you really don't want to face in the playoffs if they're riding a win streak going into the postseason.