Joe FlaccoPhil Simms. Joe Montana. Troy Aikman. Steve Young. Drew Brees. All Super Bowl winning quarterbacks. All (soon to be) Hall of Famers — except for Simms. All are Joe Flacco-like in their playoff performances. Or, perhaps, I should say Flacco is like them. Either way, the point remains: Flacco’s playoff performance stands among the elite.

This postseason Flacco has thrown eight touchdowns and zero interceptions. Simms, Montana, Young and Brees are the only other quarterbacks to throw at least eight touchdowns with no interceptions in a single postseason. Coincidentally, their respective performances propelled their teams to Super Bowl victory. Only one obstacle remains for Flacco, and it happens to be a big one.

In the regular season, there was no better defense than that of the 49ers.  They gave up only 4.7 yards per play, while allowing teams to score just an average of 17.1 points per game. They bent slightly, but never broke. Quarterbacks completed just 36.3% of passes 16 yards or more. But this trend has largely reversed in the playoffs.

In their last two matchups, the 49ers have given up 6.7 yards per play and 27.5 points per game. A big reason for this has been their inability to defend the deep pass. In their respective playoff games, Aaron Rodgers and Matt Ryan both completed 3-of-5 passes of 20 yards or more. Ruthless Sports Guy has broken down the blunders of safeties Dashon Goldson and Donte Whinter, so I won’t belabor that point. But what I will do is show why the recent struggles in the secondary are problematic against Joe Flacco.

Flacco is not just playing at an elite level because he’s not throwing interceptions, a la Simms and company. He’s playing at an elite level because he’s been accurate and efficient, especially when throwing deep.

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In the regular season, Flacco struggled with consistency. This is largely shown by his poor accuracy both when attempting deep passes and when facing pressure. However, over the past three games, Flacco has turned it on. Not only is he throwing the ball down field on one in every four passes, but he’s completing them at a rate that defies logic.

Since 2008, only four quarterbacks have thrown in deep on at least 19% of their total attempts. None of them enjoyed the nearly the success that Flacco has been having.

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As with any stat-centric post, sample size is a huge concern. Not many quarterbacks attempt as many deep throws. But this isn’t a coincidence. Deep throws have a very low success rate. This is why Peyton Manning, arguable the most efficient quarterback in the league this season, attempted such passes just 12% of the time. Last year’s Most Valuable Player (MVP), Aaron Rodgers, also attempt such passes only 12% of the time. The MVP of 2010, Tom Brady, attempted them just 9% of the time.

Good quarterbacking and the deep ball are antonyms in all cases but Flacco’s. This fact must be of huge concern to the 49ers, whose secondary has proved unable to defend it. If Goldson and Whitner make the same mistakes they’ve been making, the Super Bowl will be anything but super for the 49ers.