DETROIT — Wednesday’s game between the Pistons and the San Antonio Spurs was more than just a regular season matchup between two struggling teams in January. It was a duel between two legacy franchises with championships attached to their names and a coaching battle between mentor and mentee. Gregg Popovich, arguably the greatest coach in NBA history, was lined up against his former player and assistant coach, Monty Williams. History was made before the ball was event tipped as the game marked the second time in NBA history that two teams with 30 or more losses in 40 or fewer games played have…