Dirk Nowitzki finally in shape (unlike 2011) and healthy (unlike 2012) is shooting a blistering 53 percent from the floor in the preseason. He’s made a good enough 6-16 from long range and has missed just one free throw in 14 tries. The Mavs have won more exhibition games than they’ve lost (4-3) and Nowitzki seems ready for the six or potentially seven-month haul that’s ahead of him. With just one preseason game against the Indiana Pacers left before that 82-game slog you’d think Dirk would be ready to take in his last bit of rest and relaxation before the grind hits. Nein. On Thursday the basketball mentor that Dirk has been studying under for two decades is flying into Dallas to give Dirk’s game the once over. And Dirk is welcoming longtime personal coach Holger Geschwindner with open arms.