There's always been a bit of a disconnect between what makes an NFL cornerback popular and what makes an NFL cornerback valuable.
From 2004-2007, Lito Sheppard and Sheldon Brown manned the the Philadelphia Eagles' two outside cornerback positions. In that time, Sheppard played in 49 games, intercepted 16 passes and scored three defensive touchdowns. By contrast, Brown started all 64 games and only had 10 interceptions––he was also the one guarding the opposition's best receiver.
In those four years, Sheppard made two Pro Bowls and one All-Pro team, while Brown never received any accolades.
Since leaving Philly in 2009, Brown has assumed a starring role in Cleveland's underrated secondary, starting all 32 games in two years, and providing a stabilizing force for the Browns. Sheppard, meanwhile, signed with the Oakland Raiders last season––his third team in as many years.
The point I'm trying to get at here, is that Sheppard was the one racking up interceptions (a serendipitous statistic) and making Pro Bowls, but Brown was always the better cornerback. Sheppard was the one casual NFL fans knew about, but Brown was the one incisive NFL coaches stayed away from.
An unheralded fifth-round rookie from Stanford, Sherman is a player Pete Carroll has been eyeing since high school. Despite his status as a late draft pick, Sherman emerged as a starter by Week 8 and never looked back.
According to ProFootballFocus.com, Sherman graded out as the fourth-best coverage cornerback in the NFL last season, trailing Darrelle Revis, Lardarius Webb and Brent Grimes. The standard QB rating for passers throwing into his coverage was 57.3, the ninth-lowest for any cornerback in the league.
Like Sheldon Brown, Sherman was overshadowed last season by a less-efficient Pro Bowl cornerback, Brandon Browner. Browner made the Pro Bowl on the strength of his six interceptions, but he also lead the NFL in penalty-rate.
ESPN.com's Mike Sando took note, saying of Browner "I might have considered Browner's teammate, Richard Sherman, as a superior choice to represent the NFC at season's end."
Sherman stands 6'3" and was converted from wide receiver when at Stanford, a testament to his athleticism and fluidity.
And while he might never dominate your morning SportsCenter, he's well on his way to becoming the next premier shutdown corner in the NFL.