Both players are finalists in online voting for rookie honors through the NFL.
For our division-specific purposes, let's narrow the field to Smith and Peterson. Which one had the better rookie season?
Teams would generally value a pass-rusher over a cornerback if both were of elite status. Peterson's contributions as a punt returner give his candidacy another dimension. He scored four touchdowns on returns as a rookie. He also steadily improved at cornerback, providing hints that he'll become a Pro Bowl-caliber player at that position, too.
Smith collected 14 sacks, all in the 49ers' last 13 games. He had four passes defensed, two forced fumbles and one fumble recovery. His safety at Detroit helped the 49ers beat the previously undefeated Lions at Ford Field. Smith had two sacks and a forced fumble in that game. He played not quite half the 49ers' defensive snaps this season, coming onto the field in passing situations.
2011 Rookie Comparison
Peterson started all 16 games for the Cardinals at cornerback. He played all but a few snaps for a defense that showed great improvement as the season progressed.
Peterson had to play right away in all situations. He got little help from the Cardinals' pass rush early in the season. He also had less overall talent around him than Smith enjoyed.
Peterson finished the season with two interceptions and one sack. He returned four punts for touchdowns and blocked two field goal attempts. He was named to the Pro Bowl and an Associated Press All-Pro as a return specialist.
Smith and Peterson both met the expectations of their drafting teams.
Peterson was quite arguably the primary difference between the Cardinals matching their 5-11 record from 2010 and finishing with the 8-8 mark they eventually posted. His first punt-return touchdown came during the fourth quarter of a 28-21 victory over Carolina, breaking a 21-21 tie. His third one was a 99-yarder to beat the Rams in overtime. His final one came late during the third quarter of a 23-20 victory against the Rams.
Given a chance to draft again, the Cardinals and 49ers might make the same choices. That's how good Smith and Peterson were during memorable rookie seasons.