With the game tied at the start of the fourth quarter Thursday night, Kevon Looney clapped his hands with chalk and took the floor in front of a capacity SAP Center crowd. The only asterisk-worthy detail: Because it was the preseason, the outcome hardly mattered. Though many of his teammates labored, Kevin Durant continued to show why his offseason signing makes Golden State heavily favored to win its second NBA title in three years. After adding Durant to a group that won an NBA-record 73 regular-season games, the Warriors are staring down championship-or-bust expectations. Substitution patterns, execution of sets and health matter more to coaches than the final score. [...] Thursday, with his Warriors nursing a five-point lead late in the third quarter, head coach Steve Kerr started pulling his starters.