Going into the Free Agency Period, I felt it was good to look at the performance of top free agents over the past three years, measured in 'expected points added', or EPA. EPA tracks a player's individual contribution to the increased probability of a team scoring. For defensive players, EPA+ is used, which is a bit more complicated...all stats are taken from AdvancedNFLstats.com. I also included Carlos Rogers for comparison to other defensive backs -- for players with less than three years of significant playing time -- or a position change -- less than three years is used. Data is available below.

My 'value' guys:

- Carlos Rogers - yeah, Carlos Rogers. Compared to other free agent corners, he's performed exceptionally well. Brent Grimes is an equal bargain, but he may end up getting $10m - $12m+ a year and coming off a torn ACL, while Rogers is only $7.8m over the remainder of his contract...and his last year in SF is at age 34, that last year most guys play at an elite level at CB. So unless we plan on going with a rookie, Rogers shouldn't go anywhere.

- Danny Woodhead - all he does is convert first downs. Probably won't be that expensive

- Brandon Gibson - solid producer

- Adrian Wilson - cut due to age, but still produces. If we lose Goldson, he could be a great option.

- Cullen Jenkins - significant production from the inside

- James Harrison or John Abraham - I don't know what they're going to get on the open market, but if they're willing to accept less for a part-time role as a pass-rusher in San Francisco, it could be a good deal.