Dovetailing nicely with a piece this week by Jason Cole of Yahoo!, which details the decreasing importance of the left tackle position at a time when quarterbacks are unloading the ball quickly, there could be notable turnover at the critical pass protection spot this season in the league. For a variety of reasons that include retirement (Matt Light in New England), free agency defection (Buffalo's Demetress Bell) or shaky performance in 2011 (Doug Free of Dallas), there could be as many as seven new starting left tackles among the 32 teams in 2012. That's a pretty significant turnover for a position that, over the years, has exemplified stability. But if line coaches have been accurate with their comments from OTAs and minicamps, the projected newcomers at left tackle have progressed nicely as a group during the offseason workouts. That's been especially true of Cowboys' second-year veteran Tyron Smith, who played right tackle in 2011 after Dallas tabbed him with the ninth overall choice in last year's draft, but who will flip with Free for 2012. The Cowboys always suspected the former Southern Cal star was a left tackle, and now Smith seems to have reinforced that notion. "He's taken to it so well; (he's) a natural (left tackle), the feet, the technique, everything about him," first-year line coach Bill Callahan told The Sports Xchange. "He could be special there."