SAN DIEGO >> Prior to his first game as the Dodgers' manager, Dave Roberts reserved 13 tickets for friends and family to attend Opening Day at Petco Park. Roberts grew up in north San Diego County, so a gambling man might have taken the over on Roberts' traveling contingent.Thirteen is a lucky number in some circles, but other than avoiding the white chalk foul lines whenever he steps on the field, Roberts insisted Monday that he is not a superstitious man.