​When the Pittsburgh Steelers jump-started their ground attack, casual observers focused on Jaylen Warren’s hard-nosed running. However, advanced gap-by-gap metrics reveal that Pittsburgh’s rushing revival was driven almost exclusively by a dominant left side of the offensive line.Third-year left tackle Troy Fautanu, left guard Mason McCormick, and center Zach Frazier completely redefined Pittsburgh’s offensive trench play. On the “Locked on Steelers” podcast, beat analyst Alan Saunders highlighted advanced rushing data by gap that illustrates just how staggering the left-to-right split was.”The Steelers running left edge off the left tackle [were] plus-.5,” Saunders noted, referring to rushing yards over expected. “Inside the left tackle plus-.35, left guard and up the middle plus-0.25. They were zero at right guard, minus-27 at right tackle, and minus-48 off the right edge. All of Warren’s rushing success was left side.”Host Christopher Carter reinforced the tape study with traditional production totals, noting, “Just on the left side of the line in general, Jaylen Warren averaged like nine yards per carry. That right there, that’s a problem.”The sudden left-side dominance isn’t an accident. Both Fautanu and McCormick were elite run blockers in college before making their respective position transitions, while Frazier has already established himself as one of the NFL’s premier young interior anchors.”There’s good reason to think that those guys three games into playing on the left side now are going to get back to being dominant run-blocking linemen,” Saunders explained.While pass protection remains a work in progress for the young front, the left side has established a clear physical identity. If Pittsburgh continues running behind Fautanu, McCormick, and Frazier, they have built a sustainable blueprint to overpower defensive fronts for the rest of the season.This article originally appeared on Steelers Wire: Why the Steelers’ left side is suddenly an elite run-blocking unit