DENVER — Sometimes, first-year Astros manager Bo Porter doesn’t have full control of his daily lineup. Outfielders Brandon Barnes and J.D. Martinez know they have absolutely none. Same for shortstop Ronny Cedeno and first baseman Carlos Pena. The rebuilding Astros are an on-the-field experiment, blending advanced statistics and raw youth with Porter’s growing intuition and a few low-cost, well-traveled veterans. The club’s constantly changing, slowing evolving lineup is proof. Through 53 games, the Astros have employed 43 unique batting orders. Barnes again hit leadoff and played center field in Wednesday’s 6-3 win over the Colorado Rockies at Coors Field. With no designated hitter, Cedeno batted eighth and held down shortstop, [...]