The Pistons keep moving pieces, and now are moving places, back downtown for the first time in decades. And yet, three years into the Stan Van Gundy regime, the question still simmers: Where are they going? This is a riddle seeking a rhyme, as the Pistons open the season tonight with another potential cornerstone addition, Avery Bradley, another promising draft pick among five new faces, another push for more. When owner Tom Gores gave Van Gundy a five-year, $35-million contract in 2014 to take complete charge of personnel, in addition to coaching duties, he also purchased patience, but not an unlimited amount. Van Gundy is a respected basketball mind who made the playoffs each of his seven full seasons as an NBA coach before taking over a franchise in disarray. Since then, the Pistons have reached the playoffs once in three years and are yet to establish a firm direction. For every positive sign, there’s an uncertainty. No one’s picking them to challenge the best in their conference — Cleveland, Boston — but in the watered-down East, they absolutely have the talent to return to the postseason, and they should. As they leave their longtime home at the Palace of Auburn Hills for glittering Little Caesars Arena, the lights get brighter, and yes, hotter.