San Francisco had Green Bay's number in 2012, marking the Packers' season with bookend losses.
Alex Smith and the 49ers stunned the Pack to open the regular season, delivering Green Bay a 30-22 loss at Lambeau Field.
In that game, Smith had a 125.6 QB rating, completing 20-of-26 passing for 211 yards and two touchdowns. His performance was balanced by Frank Gore's 112 rushing yards and one touchdown.
It was a very different San Francisco team that once again stunned the Packers with a 45-31 decision in the NFC Championship game.
This time it was Colin Kaepernick that had the Packers' number, running roughshod for 181 yards and two touchdowns in addition to throwing for 263 yards and two touchdowns.
"We're studying the read option, the teams that are doing it in the NFL," said Mike McCarthy when asked about the game at the NFL Scouting Combine.
"We're even going to the college ranks, we'll have a couple college coaches come in, spend some time with our staff."
The Packers will even go as far as traveling to Texas A&M to meet with head coach Kevin Sumlin and his staff regarding the most recent offensive scheme to take the NFL by storm.
It is something Green Bay has to take seriously as a team that has the focus of reaching the Super Bowl each year.
The 49ers have not only established themselves a prime team to beat for the NFC Championship, the Packers will once again meet them in the regular season in 2013.
"You look at the difference in the first game and the second game, and obviously the glaring statistic and the information in the second game was obviously the production of their quarterback," said McCarthy.
"So you evaluate the scheme, you evaluate the fundamentals. We need to improve No. 1 as a football team, that won't change. We'll put tremendous emphasis on our younger players, particularly the rookies, to take a big step in year two."
As much as the read-option offense tangled the Packers' defense and kept them from reaching the Super Bowl, the bottom line is missed assignments.
"It's about trusting the guy next to you," said McCarthy. "And particularly (when) you get into misdirection, read option, obviously, the extra gap is not accounted for because the quarterback is not part of the equation of running the football.
"So they executed that at a high level."
The read option actually wasn't much of a factor for Green Bay until the second half.
"We really had issues in the first half with the pass rush," said McCarthy. "That's really what our conversation on the headsets were during the whole first half and, particularly, halftime was the pass rush and keeping Colin in the pocket.
"Then, obviously, it became a read option more in the second half."
McCarthy is determined to stay on the front side of this offense that has cycled in to the NFL with teams like San Francisco, Seattle and Washington – all NFC teams.
But defending against the scheme is where it stops for McCarthy.
"We won't run it with our quarterback if that's what you're concerned about."