Predicting The NBA Upset: Regular Season Games

Upsets in the NBA, whether during the regular season or the playoffs, seem to always come as a surprise.  However, they occur regularly.  

Every season there are times when a good team loses to a really bad team; and nearly every postseason, there is a time when a higher seed loses to a lower seed.  

This is more surprising in the NBA because it is a seven-game series to decide the winner. The lower seed doesn't just have to win once; they have to win four times.  This is no easy task and no amount of buzzer-beaters can help a team win four out of seven. They have to be the better team to win.  

There is the one-game regular season upset, and the four-game post-season upset. These are different beasts. 

The one-game upset: an upset is a game where the better team loses and is clearly better.  They have superior players, athletes, etc.  

This season, there are three top-caliber, "celebrity" teams: the Lakers, Cavs, and Celtics. Each has been upset at least once, losing to a really poor team.  

The Lakers have lost at Charlotte (by ten), hosting Charlotte (by seven in OT), and at Sacramento (by twelve).

The Celtics have lost at Golden State (by ten), at New York (by twelve), at Charlotte (by eight in OT), at the Clippers (by two), at Milwaukee (by nine).

The Cavaliers have lost at Washington (by two), at Washington (by eight).  

An interesting question is: what is the expected chance of losing to a bad team by a marquee team?

Anyways, these are the games I would call regular season upsets.  Nine of the ten games are on the road.  Washington vs Cleveland are rivalry games, Charlotte just has LA's number, and the Celtics are the unpredictable ones.  

But the million dollar question is: why did this happen?  

It's a mystery.  

Why do these superior teams lose to bottom of the barrel teams?