What does impact mean - bc to me that would be pro bowlers - so clearly your definition is needed 3drdre
In my little chart, impact players were starters that deserved to be starters and made an impact that contributed to winning. Ruud in '07 and first 12 games of '08 is a good example. He didn't make the Pro Bowl (which is far too much a popularity contest) but his numbers were at or near the Pro Bowlers level. Penn and Joseph are impact players, T-Jax was, Talib is, Adams and Clayton are not.
How about a starter, that would start on most teams?