NASCAR president Steve Phelps pushed back Friday on criticism of the Championship 4 field, stating that three of the four drivers racing for a championship at Phoenix Raceway this Sunday won their way in and that the playoff format has delivered “incredible racing.” “The format is the format. And we are always looking if there are opportunities for us to tweak something, so be it,” Phelps said. “We are not the only sport where the best statistical team does not get to the Final Four or the Super Bowl or the World Series. The format — there was a huge emphasis put 10 years ago when the format w…