Winning an NBA championship is a hard thing to do. After all, only one out of the 30 teams can do it each year.

And each year is different. For example, in the 1994-1995 season, the Houston Rockets won the title with a net rating (points scored per 100 possessions minus points allowed per 100 possessions) of 2.44. That ranked 11th in the league that year, and would have been behind two teams this year in the Timberwolves and Suns that didn't even make the playoffs.

Sometimes the second-best team of a particular year would have easily been the best team in another year. We all know how short title windows are - sometimes you're the right basketball at the right time. Sometimes, you aren't.

In honor of those teams, let's look at the five best teams of the past 30-ish years (since the 1985-1986 season, as that is the first season for which we have offensive and defensive ratings available). As a caveat, this is purely by the numbers and isn't my personal opinion. I know that a team that had a net rating of 9.0 could have very easily had a rating of 4.0 in a different season. But we have the numbers that we have, so this is how we're going to do it.

5. 1996-1997 Utah Jazz

Adjusted Offensive Rating: 113.94
Adjusted Defensive Rating: 105.23
Adjusted Net Rating: 8.71

This Jazz squad had the rough luck of existing during the Michael Jordan era in Chicago. Their 8.71 net rating was second-best that year, but it was still well behind the Bull's rating of 11.82, which is all-time great. For perspective, the Jazz's rating would have been the best in the league last year, even ahead of the Spurs.

They were led by Hall of Famers John Stockton and Karl Malone, and took the Bulls to six games in the Finals. They also had an extraordinary amount of injury luck, with their best three players - Stockton, Malone, and current Suns head coach Jeff Hornacek - all playing the full 82 games. In a different time, Stockton and Malone likely would've gotten their elusive title.

4. 1993-1994 Seattle SuperSonics

Adjusted Offensive Rating: 111.55
Adjusted Defensive Rating: 102.71
Adjusted Net Rating: 8.84

The SuperSonics will forever kick themselves after blowing their opportunity in the 1994 playoffs. Michael Jordan was playing baseball, they had the best record and net rating in the league (by a wide margin, too), and they were up 2-0 on the eighth-seeded Denver Nuggets in the first round of the playoffs.

They ended up losing three straight to the Nuggets to become the first number-one seed to lose an eighth seed. The Houston Rockets, led by MVP Hakeem Olajuwon, ended up taking home the title with only a 4.34 net rating, one of the worst ever for a champion. Eventual Hall of Famer Gary Payton ended up getting his title in 2006 with the Dwyane Wade-led Miami Heat, but he surely would've loved to bring home a title to Seattle in 1994.

3. 2000-2001 San Antonio Spurs

Adjusted Offensive Rating: 107.20
Adjusted Defensive Rating: 98.31
Adjusted Net Rating: 8.89

The Spurs, led by David Robinson and Tim Duncan, easily had the best net rating during the regular season. In fact, their mark of 8.89 more than doubled the 4.01 one that the eventual champion Lakers posted. But once the playoffs came, everything changed.

The Lakers set records in those playoffs, going a ridiculous 15-1 in the playoffs en route to their title, including a 4-0 sweep of the Spurs in the Western Conference Finals. The Spurs just ran into a historically great playoff run at the wrong time. But it didn't end that badly for the Spurs - the very next month they drafted a point guard from France who has since led them to multiple championships, Tony Parker.

2. 2008-2009 Cleveland Cavaliers

Adjusted Offensive Rating: 113.18
Adjusted Defensive Rating: 103.37
Adjusted Net Rating: 9.81

Despite losing in the Eastern Conference Finals to a Dwight Howard-led Orlando Magic team, this was probably the best of LeBron James' early Cavalier squads. They tore through the regular season, posting a 9.81 net rating, which was significantly better than any other team.

If there was any season for LeBron to win a title during his early Cleveland days, this season was it. They were the best team in the league with the best defense in the league. They also had the best player in the league, as LeBron put up a crazy 31.7 PER in a MVP season. If this season played out again, it's likely that the Cavs win it all and LeBron never goes to Miami.

1. 2012-2013 Oklahoma City Thunder

Adjusted Offensive Rating: 113.21
Adjusted Defensive Rating: 103.33
Adjusted Net Rating: 9.88

We can't feel too bad for LeBron, however, since he didn't have to face this Thunder squad on his way to his second title. Their 60 wins and net rating of 9.89 was easily championship-caliber.

This may always be the greatest what-if team. Before the season, they famously traded James Harden away to the Houston Rockets. Then, ironically, Russell Westbrook tore his meniscus playing those very Rockets in the first round of the playoffs. They eventually lost in the second round to the Memphis Grizzlies, but they would have been the title favorites if either Westbrook had stayed healthy or James Harden had stayed in Oklahoma City. If Kevin Durant and the Thunder never get a title, this what-if season will haunt people of Oklahoma City for the rest of time.