From Jeff Gluck's article:
The Top Five: Breaking down the Las Vegas playoff opener
The second half of the Cup Series schedule has completely come alive with a string of entertaining, enjoyable, unpredictable races. The Bristol night race was close to racing perfection, and that came on the heels of a fantastic Watkins Glen race that was excellent from start to finish. Chicago (“Slide Job!”) was a classic. Daytona had a fun new winner (“How about that race, boys and girls?”), New Hampshire was unexpectedly entertaining for flat-track standards and Indianapolis had a thrilling finish.
Then came Sunday in Las Vegas, which turned out to be one of the craziest playoff openers NASCAR has seen. And it happened at a 1.5-mile track, at that!
“A certain element to motorsports will always be that we play a game of chicken,” Keselowski said. “Whether it’s on restarts or whatever scenario it might be, understanding who has what stakes on the line is really important.
“When one person pushes you hard and then you let them in or let it go, then eventually someone else does it, and now you find yourself in the back playing from behind, and now you start to do it. It creates an escalating effect.
“With that in mind, eventually both guys don’t lift, and things happen. With that said, the playoffs, of course, when you’re playing from behind can make you take more risks.”
http://jeffgluck.com/the-top-five-breaking-down-the-las-vegas-playoff-opener/