The early-season showdown between the San Antonio Spurs and the defending champion Golden State Warriors on Thursday is a prime example of how the eight-month NBA campaign is a marathon, not a sprint. When the two teams square off at the AT&T Center for the first of three regular-season contests, a look at the standings will show that the Spurs and Warriors have had their difficulties over the first three weeks of the year, losing a combined six games already after meeting in the Western Conference finals last year. Golden State (5-3) heads to the Alamo City on the heels of a 141-113 rout of the Los Angeles Clippers on Monday, which came a day after the Warrior fell at home to the Detroit Pistons.