1. How will the Ravens fare against the read option? San Francisco’s first two playoff games have been a perfect example of why the read option can be so difficult to defend. Against Green Bay in the divisional round, 49ers quarterback Colin Kaepernick ran all over the Packers, racking up 181 yards. Determined not to let that happen the next week, the Atlanta Falcons did a good job taking away Kaepernick’s running lanes — but left too much space between the tackles and the 49ers still managed 149 yards on the ground. In preparing for Kaepernick, the Ravens can turn on their game tape from Week 14, when they faced Robert Griffin III of the Redskins. RG3 gained 34 yards on seven carries in that game before being hurt in the fourth quarter. Similar numbers by Kaepernick today would be a big success for the Ravens.

2. How will the 49ers fare against the deep ball? No quarterback has thrown deep down the field as much as the Ravens’ Joe Flacco. According to ESPN Stats and Information, Flacco has attempted 101 passes that have traveled at least 21 yards in the air. The improvement has come in how many of those he’s completing. In the first 13 games, his completion percentage was 34.2. After the Ravens replaced Cam Cameron with Jim Caldwell as offensive coordinator, Flacco’s completed 53.6 percent of those passes. The Ravens have better balance under Caldwell, running the ball 49 percent of the time. That has opened things for Flacco. Also according to ESPN Stats, the 49ers have allowed just three touchdowns on passes that have traveled at least 21 yards in the air. Opponents are completing just 29 percent of passes of that length although the 49ers have struggled a bit of late in this department. Atlanta’s Matt Ryan hit Julio Jones on a deep pass for a touchdown in the NFC Championship game.

3. Opposite strengths in red zone. San Francisco has shown big improvement since the end of the regular season in the red zone. The 49ers have scored seven touchdowns on nine trips inside the opposition’s 20-yard line in their two playoff games, a 78 percent success rate. That’s up from 51 percent in the regular season. The Ravens, on the other hand, have carried over their defensive success in the red zone from the regular season. They allowed touchdowns on just 43.4 percent of red zone trips by their opponents in the regular season. They’ve dropped that number to 40 percent in the playoffs.

4. Endurance issues on defense. The Ravens have played 1,342 defensive snaps this season, the most in the NFL since 2001. The 49ers have had nine players play at least 90 percent of their defensive snaps. No other team had more than six, according to ESPN. San Francisco had better success in the regular season, allowing just 17.1 points per game, which was second in the NFL. That’s a good omen. Teams finishing in the top two in that category are 16-5 in the Super Bowl (when not facing another top-two team) and have won eight straight games.

5. Harbaughs not afraid of bold decisions. Give the Harbaugh brothers credit: they’re willing to take risks. San Francisco’s Jim named Kaepernick the starter after Alex Smith suffered a concussion at midseason. Baltimore’s John replaced Cameron as offensive coordinator with just three weeks left in the regular season. It wouldn’t be a surprise either head coach try to catch his brother off guard with trick plays.

Outlook: With teams this physical, the pads should be popping today. The Ravens believe they’re a team of destiny, but the 49ers are slightly more talented, and that will win out.

Prediction: San Francisco 27, Baltimore 23