It was just a couple of years ago, but it seems so long ago. It was on April 10, 2015 that Pittsburgh Steelers All-Pro safety Troy Polamalu announced that he would be retiring from the NFL following a career that spanned 12 seasons, two Super Bowl rings, eight Pro Bowls, and four nods to the first-team All-Pro list, with another on the second team. He finished the 2010 season as the Defensive Player of the Year.
It is quite simply a difficult thing to attempt to quantify what Polamalu meant to this defense, but the best way to explain it would be to watch the Steelers when he was on the field and then when he was out with one of his many injuries.