To understand the way today’s NBA works, it usually helps to study the Golden State Warriors.

Let’s start with a game last month against the Boston Celtics that was closely scrutinized around the league as a potential Finals preview. Golden State took a 17-point lead in the second half. Boston won by ripping off 19 straight points in response.

The exact opposite happened the next time the Warriors took the court. Philadelphia was up 24 points. Golden State roared back with a 47-13 run in what turned out to be the best third quarter in NBA history.

These were some of the most exciting games of the season between teams with some of the league’s most compelling players. They were also the latest evidence of a strange idea spreading across the NBA: It has never been more dangerous to have a big lead.