Do the best teams really win the close games?

It seems to be a popular theory that the best teams in the NBA are those who execute down the stretch and win close games. Therefore, it would stand to reason that the best teams would have the best records in close games. However, this is not the case.

Here are the records of teams in games decided by three points or fewer in 2007-2008:

Portland Trailblazers...10-2
Golden State Wariors.....9-2
Houston Rockets..........9-3
New Jersey Nets..........7-3
New Orleans Hornets......8-4
Detroit Pistons..........5-3
San Antonio Spurs........8-6
Charlotte Bobcats........8-6
Utah Jazz................4-3
Indiana Pacers...........4-3
Chicago Bulls............4-3
Sacremento Kings........10-8
Cleveland Cavaliers.....10-8
Atlanta Hawks............6-5
Boston Celtics...........7-6
Denver Nuggets...........6-6
Orlando Magic............6-6
Torono Raptors...........3-3
Dallas Mavericks.........5-6
New York Knicks..........4-5
Seattle Supersonics......5-7
Milwaukee Bucks..........6-9
Los Angeles Lakers.......5-8
Washington Wizards.......5-9
Phoenix Suns.............3-5
Philadelphia 76ers.......4-8
Minnesota Timberwolves..4-8
LA Clippers..............2-5
Miami Heat..............3-11
Memphis Grizzlies.......2-11

This certainly does not look as though the best teams had the best record in close games. Unless, of course, you believe that the New Jersey Nets, Golden State Warriors, and Portland Trailblazers are three of the top five teams in the NBA. Also, the Lakers (who are considered to be one of the best teams in the NBA), fared among the worst in these close games. An argument could be made that these are small sample sizes and therefore statistically insignificant. This is not necessarily the case. For instance the Lakers record of 5-8 in close games would only happen by random chance 1.5% of the time. Therefore, it seems clear that in many cases, a team's record in close games has nothing to do with how good the team is.

On the contrary, a team's record in blowouts seems to be a much better indicator of how good a team is. Here are the records of teams in games decided by 10 or more points:

Boston Celtics............45-3
Los Angeles Lakers........37-9
Detroit Pistons..........37-10
Phoenix Suns..............31-9
Orlando Magic............34-12
San Antonio Spurs........31-11
Houston Rockets..........31-11
Utah Jazz................37-14
Dallas Mavericks.........29-11
New Orleans Hornets......37-15
Toronto Raptors..........26-16
Denver Nuggets...........29-18
Golden State Warriors....22-14
Washington Wizards.......26-19
Philadeplphia 76ers......18-20
Sacremento Kings.........17-23
Portland Trailblazers....15-22
Chicago Bulls............19-29
Indiana Pacers...........14-22
Cleveland Cavaliers......10-17
Charlotte Bobcats........12-24
Atlanta Hawks............11-24
Los Angeles Clippers.....10-35
Memphis Grizzlies........10-37
New Jersey Nets...........8-31
Minnesota Timberwolves...8-35
New York Knicks...........6-33
Milwaukee Bucks...........5-29
Seattle Supersonics.......5-37
Miami Heat................4-34

This looks a lot more like a ranking of the best teams. The top twelve teams all made the playoffs. It appears as though the teams that win blowouts are much likely to be better teams than those who win close games.

John Hollinger stated it well in a recent chat on ESPN.com:

Will (NYC): I agree that some close games are 50/50 but those are in the minority. A big part of being a great team is the ability to show heart and win the close games. It's called performing under pressure and that is something that Boston showed they may be lacking greatly. That is why people are less confident in their chances.

John Hollinger: A lot of people believe that, but the evidence it isn't true is just overwhelming. Look at any team that was together for a number of years, even the great ones -- Jordan's Bulls, for instance -- and you'll find that the closer the score, the closer they are to .500. In other words, in games decided by two points or less they'd be almost exactly .500, even a team like the Bulls; in games decided by 15 points or more they'd be nearly 1.000. It's a fallacy that the good teams win the close games; the good teams win by 20. The lucky teams win the close games. There is no team in history that's been able to defy the correlation between scoring margin and wins over an extended period.