After beating the two greatest quarterbacks of a generation in Peyton Manning and Tom Brady, the Baltimore Ravens should have little fear of a quarterback making his 10th NFL start. But the San Francisco 49ers' Colin Kaepernick is a completely different threat as he represents the next generation and an offensive system that is changing the sport.

It took a torn ACL to quarterback Robert Griffin III to stop the Washington Redskins' zone read offense. Nobody really stopped the version run by Russell Wilson and the Seattle Seahawks. Their playoff loss in the divisional round came because the Atlanta Falcons got the ball last.

Now there is one team left running the read option, a defense for which has yet to be found. Some coordinators have attempted exotic alignments. Others have tried to "spy" the quarterback. Some teams have ordered their ends or outside linebackers to seal the edge. Others have attacked. Others still have sat back and reacted. Nothing seems to be working.

After the Packers surrendered 323 yards rushing to the Niners in a 45-31 loss in the divisional round, nose guard B.J. Raji explained the dilemma of stopping the read option to

"When the quarterback can run like that, that opens up the arsenal of play calling. Obviously if you can't stop the run, that's football 101," Raji said. "We just didn't have an answer."

Against the Redskins, Ravens lineman Haloti Ngata had the best answer, hurtling his 6-foot-4, 340-pound body into the path of Griffin on a scramble and knocking him from the game. Baltimore still lost that game 31-28 in Week 14, but it was all the good things the Redskins did earlier that set up the shootout victory.

The Ravens defended the read option as the game progressed but still yielded big chunks of yardage to Griffin (15-for-26, 242 yards) and Alfred Morris (23 carries, 129 yards). Startling was the ease with which Washington ran up and down the field, driving 80 and 83 yards on its first two possessions and facing third down only twice.

That kind of defense will not get it done against a San Francisco team that mimicked the early success of the Redskins and Seahawks but stands to gain the most from the innovation.

- Kevin Dunleavy