Navy goes west, Air Force goes blue and Army West Point goes … well, goes to West Point … as the college gridiron season enters the home stretch. What service academy football fans need to know this week: 1. The basics. Before launching into conference tiebreaker procedures, national rankings and a handful of what-if scenarios, here’s the slate for the coming weekend: Air Force (7-3, 5-1 Mountain West Conference) visits the blue field of Boise State (7-3, 4-2 MWC) on Friday night for an MWC Mountain Division showdown (9:30 p.m. Eastern, ESPN2). Army West Point (2-8) concludes its home schedule Saturday (noon…