In the front yard of Ruben Niebla’s childhood home, a small rectangular patch of grass served as a baseball infield. In the carefree days before a fence was installed and a tree grew high in the approximate spot where the mound would be, outfielders fanned out along John Kennedy Street as balls made from tape or socks whistled through the neighborhood.This is where baseball really began for Niebla, the Padres’ pitching coach and one of the most respected mound mentors in the Major Leagues. It’s where he crammed his hand into his first glove. It’s where his dreams gained shape and wings.It’s...…In the front yard of Ruben Niebla’s childhood home, a small rectangular patch of grass served as a baseball infield. In the carefree days before a fence was installed and a tree grew high in the approximate spot where the mound would be, outfielders fanned out along John Kennedy Street as balls made from tape or socks whistled through the neighborhood.This is where baseball really began for Niebla, the Padres’ pitching coach and one of the most respected mound mentors in the Major Leagues. It’s where he crammed his hand into his first glove. It’s where his dreams gained shape and wings.It’s...WW…