Home-court advantage means less than ever in NBA. Why?

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Last night, the Cavaliers, Raptors, Bucks, Grizzlies, Bulls and Wizards won. The Pistons, Pacers, Heat, Mavericks, Warriors and Lakers lost. There were good games and routes, highlights and sloppiness.

It was a pretty standard NBA night, with one exception:

Road teams went 6-0.

Really, that’s becoming standard.

Visiting teams have won 46 percent of their games this season, the highest mark of all-time (hat tip: Zach Lowe of Grantland). The all-time mark is 38 percent and was 39 percent just two seasons ago.

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Why has this happened? I don’t know. But here are a few theories:

Better travel accommodations

The rise of teams taking private rather than commercial flights certainly played a large role in road teams improving in the 1990s.

But why this sudden uptick in road success relative to the past few years? Have NBA teams suddenly gotten even better at shuttling their players from city to city?

Fewer back-to-backs

Visiting teams have been on a back-to-back just 33 percent of the time this season, well down from the NBA’s early years, when road teams had usually played the day before.

But road back-to-backs are slightly up this season due to the extended All-Star break. So, again, that wouldn’t explain the road improvement relative to recent seasons.

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Interestingly, visiting teams have made much sharper gains in winning percentage when on a back-to-back (blue) than when not (orange):

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So that leads to a sub-question: Why have visiting teams improved so much more on back-to-backs than on games after a rest day?

Unbalanced schedule

Perhaps, the schedule just happened to work out that better teams have more early road games, and this trend will reverse in the season’s second half.

There’s no perfect way to evaluate when we should expect teams to win.

But, using current records, the home team has had an equal or better record than the visiting team 52 percent of the time so far this season. That’s just 48 percent the rest of the season.

So, it doesn’t appear this will self-correct.

Better refereeing

A common belief is home-court advantage reveals itself primarily through officiating. Referees, the theory holds, are prone to accommodate home fans.

In some versions of this explanation, referees do this subconsciously. In others, the refs are intentionally favoring the home team at the direction of the league office in order to please ticket buyers.

Regarding the former, the NBA now has technology to better train referees.

Regarding the latter, NBA commissioner Adam Silver has been much more transparent about refereeing than David Stern ever was.

Coincidence

This could just be dumb luck pushing a small trend toward what appears to be a large-scale change in the game.

There are dozens of other theories, some discussed by ESPN’s Tom Haberstroh here and Grantland’s Bill Simmons and Zach Lowe here. I haven’t even mentioned any that explain why home teams could be worse. I’ve focused only on why road teams might do better.

The truth is, I don’t know, but I’m open to ideas. Have any?