In our first installment of the “Rookie Richter,” we grade the guys who really pound the earth when they move — offensive linemen. After hunkering over hours of coaching tape, closely evaluating their debut performances, here are the blockers who made the greatest — and weakest — impacts for their teams.

It’s an odd (and occasionally unpleasant) sight to see linemen legging out 40-yard dashes, and most NFL talent evaluators feel the same way. While a 40 time offers a window into a prospect’s athleticism, it really has no bearing on his overall evaluation.

The first group of offensive linemen just completed 40-yard dashes at Lucas Oil Stadium, and we have some unofficial times.

In his latest position review for the 2011 Scouting Combine, NFL.com analyst Bucky Brooks unveiled his breakdown of the top five tackles and top five centers/guards scouts will be watching in Indianapolis.

NFL.com analyst Bucky Brooks takes a closer look at why their performances at the NFL Scouting Combine will be vital for Boston College OT Anthony Castonzo and Georgia G Clint Boling.