Three things to watch for Friday night in the San Francisco 49ers' second exhibition game of the 2013 season, set for 8 p.m. ET at Arrowhead Stadium:1. QB comparison. Former teammates Alex Smith and Colin Kaepernick have competed before, but never on opposite teams. That changes in this game. We're past analyzing the 49ers' switch from Smith to Kaepernick last season. The quarterback comparison in this matchup is for fun, nothing more. Will the 49ers sack Smith or pick him off?