So now it's official. Not only can the Golden State Warriors lose this season, they can even lose at home.
Boston pulled off the surprise Friday night, going into Oracle Arena and stunning the reigning NBA champions 109-106. Even with the loss, Golden State - still 68-8 on the season - remains on pace to top the 72-10 mark set by the Chicago Bulls in the 1995-96 season for the best record in NBA history.
It was Golden State's first loss in its last 55 home regular-season games.
''It takes a lot out of you,'' Warriors coach Steve Kerr said after the loss in Oakland, California, ''especially when every game is the other team's biggest game. People are coming after us.''
There are some factors to take into account, of course. The Warriors are still without Andre Iguodala because of an ankle injury, and lost center Andrew Bogut in the second half Friday with a rib injury. And Friday's game was Golden State's 24th in of 42 days since the All-Star break. So it's a safe bet fatigue entered the equation as well.
''You've got to tip your hat to them,'' Celtics guard Isaiah Thomas said.
Still, there are trends from the eight losses that might serve as a blueprint for those teams trying to beat the Warriors in the looming postseason.
Here's a look:
In the Warriors' losses, Stephen Curry (who has played in seven of them, sitting out the other with injury) has been his typical MVP-level self. He's averaged 28 points, 5.7 assists and 5.6 rebounds in the games where he's played and Golden State has been beaten.
So obviously, he's not exactly getting shut down.
But keeping the other ''Splash Brother'' in check has proved vital to opponents.
Klay Thompson's numbers in Golden State's eight defeats have been, by his standards, plebian. He's shooting 39 percent in losses, 23 percent from 3-point range, averaging just 3.5 rebounds and 2 assists as well.
In Golden State's wins, of which he's appeared in 66, Thompson is shooting 48 percent, 45 percent from 3-point range. And when he makes more than half his shots, the Warriors are 24-1.
Thompson's line in the loss to Boston: 6 for 16 from the floor, and only three points despite playing the entire fourth quarter.
DON'T LET THEM GET AWAY
When the Warriors get a double-digit lead, they win.
That's automatic, at least this season. There have been 63 in which the Warriors led by 10 points or more. They're 63-0 in those games, though some of them have certainly been highly eventful down the stretch.
On Friday, Boston's biggest deficit was midway through the second quarter when it trailed by seven points.
That's the largest one successfully overcome by a Golden State opponent all season, with the other leads that the Warriors lost in their first seven defeats being three, two, six, three, two, five and three points, respectively.
The other critical thing Boston handled was not giving up a big run. Golden State's top unanswered spurts were a pair of 6-0 runs, one at the start of each half.
OFF NIGHTS (ALMOST) REQUIRED
Boston did what almost no one has this season. The Celtics beat Golden State on a night when the Warriors weren't having what could be described as an ''off'' shooting night.
The Warriors made 46 percent of their shots. Going into the game, Golden State had been 56-1 this season when shooting that well from the floor.
When the Warriors are off, they've been doomed. Luckily for them, it doesn't happen often. When shooting less than 41 percent, Golden State is 2-6 this season.
Also, if the Warriors go up to 50 percent shooting, they win. They've won their last 66 games when making at least half their shots, including playoffs. The last time they shot 50 percent in a loss was Nov. 11, 2014 - against San Antonio.
WIN THE HALF
Getting the halftime lead has been a prerequisite to beating the Warriors.
Boston was up only 45-43, but a lead is a lead - and the numbers say that if the Celtics didn't have even that slight margin, they would have lost.
Golden State is 60-0 when leading at halftime. When the Warriors trail at the break, they are a mere 8-8.
SLOW IT DOWN
Last and possibly deservedly least, because it's far easier said than done, would be this tip: Slow them down.
Many have tried.
Most have failed.
But when the Warriors don't score 100 points - though this rule didn't apply Friday - they're 1-5 this season. When they reach the century mark, they're 67-3. And when they get to 111 points, they're a perfect 53-0.