This week’s Fourth-and-Short has four more thoughts on the four conference championship teams. In the cases of the 49ers and Ravens, it’s time to begin the arduous process of breaking down the Harbaugh Bowl. With the Falcons and Patriots, now is a good time to reflect and anticipate how the runners-up might look and act differently in 2013.

Baltimore Ravens

The Ravens truly are a combo-breaker in terms of postseason narratives. Of course, they’re a stern argument against the concept of “playing your best football when it matters” in terms of how that applies to getting hot at the end of the regular season; the Ravens really are playing their best football when it matters, but it’s come after a 1-4 end to the regular season. They’re a team that’s proved how little previous postseason performance means, as the same team that seemed to slip in game after game against the Patriots and Steelers just blew out the Patriots on their own field.

And they’re an argument against the idea that there’s a “team of destiny” in the postseason, because no team with any sort of destiny would ever leave things to such a slim chance as the Ravens did during the divisional round against the Broncos. I ran the numbers based on the 2 percent chance that the Ravens would win after getting the ball back near the end of regulation against the Broncos and the 24.3 percent chance that the Vegas money line gave them of beating the Patriots at home last Sunday. Baltimore’s odds of making the Super Bowl on first down of that final fateful regulation series against the Broncos were at 0.49 percent, making them a long shot of about 206-to-1. Think about that: You could put more than 18 full seasons’ worth of playoff games into that exact situation, and you’d see a team make a comeback and make it to the Super Bowl exactly once. Maybe the Ravens really are a team of destiny.

Notably, the Ravens have now won two consecutive games as huge underdogs. Although lines shift throughout the week and vary at different books, Baltimore was an 8.5-point underdog against the Broncos and a 7.5-point underdog against the Patriots, winning both games outright. Has any team ever done that in the playoffs before? And does it mean anything for their playoff future? Yes and no. There are two teams that have pulled this same trick — beating two teams as 7.5-point or more underdogs in one playoff bracket — but they both pulled off their trick in the Super Bowl. Those two teams were among the more legendary upset-producing underdogs in league history: the 2001 Patriots and the 2007 Giants.

Baltimore is unlikely to face such a heavy burden this week, since it’s all but certain they won’t sniff the other side of seven. The Niners opened as 4.5-point favorites in most places, and while that figure fell to 3.5 points at times that night, it’s settled at 4 points since. The public agrees: The Ravens are just too good to be massive underdogs.

San Francisco 49ers

Where, oh where, has my pass rush gone? The Niners were once a formidable unit, producing sacks in bunches with star second-year man Aldon Smith at the helm. Nowadays, the San Francisco defensive attack spends most of its time in coverage, and the pass rush hasn’t remotely stepped up to make any plays. The 49ers sacked Matt Ryan just once in 43 dropbacks Sunday, a stunningly low figure for a quarterback who was admittedly protected by simple route combinations on short throws, and even that sack was for zero yards.

If that were one game, it would be an aberration, but the San Francisco quarterback attack has spent their playoff run on their backs, not the quarterbacks’. Through the first 13 and a half games of the year — with defensive end Justin Smith healthy and active — the 49ers sacked opposing quarterbacks once every 14.9 dropbacks, a 6.9 percent ratio. Since Smith suffered a triceps injury against the Patriots, he hasn’t been the same guy, an injury that’s been reflected in the numbers. From that second half onward, the 49ers have sacked opposing quarterbacks seven times in 190 dropbacks, for a rate of 3.7 percent (or once every 27.1 dropbacks). In other words, the 49ers have seen their pass rush basically cut in half by the injury.

Even more noticeable is how good the Baltimore offensive line has been in keeping opposing defenders off of Joe Flacco. I mentioned in my Ravens-Patriots preview that the Baltimore offensive line had improved, and the Ravens kept that up against New England. Since Bryant McKinnie entered the lineup in wild-card weekend, the Ravens have allowed just four sacks on 95 Flacco dropbacks. That’s stunning pass protection, and when you combine it with the seeming ineffectiveness of the San Francisco pass rush, you get a recipe for lots of time in the pocket for Flacco in New Orleans.

Atlanta Falcons

Did you like watching the Falcons break through and nearly make it to the Super Bowl this season? Well, hope you caught them while you could. Even if Atlanta makes it to a Super Bowl with Matt Ryan at the helm, not all of his 2012 teammates will be joining him. The most obvious is tight end Tony Gonzalez, who’s “97 percent” sure he’s retiring after 16 scintillating NFL seasons. Robert Mays already covered Gonzalez’s legacy, so let’s move on to the others.

That group starts with Michael Turner, the halfback who went from focal point of the Atlanta offense to a player Falcons fans seemingly forgot about after he suffered a second-half injury. Turner has a $5.5 million salary for 2013, but most of his salary can be cut off the books if he’s released. With his role reduced and his speed diminished, it’s likely he’ll be given a chance to test free agency again. Cornerback Dunta Robinson is also guaranteed only $3 million of his $8 million 2013 salary, so the Falcons might let him go after an uneven Atlanta career that’s seen him struggle to live up to expectations after signing a big-money deal to leave Houston.

It continues with their younger players, too, with free agents abounding. Left tackle Sam Baker and safety William Moore are free agents after this season, as is cornerback Brent Grimes, who played only one game with the team before being put on injured reserve. It’ll be very interesting to see how the Falcons use their limited cap space this offseason. Their best bet would be to re-sign Moore at all costs and find a free-agent replacement for Turner, since nobody wants an old back who can’t catch passes on the field. As for replacing Gonzalez, yeah, have fun with that.

New England Patriots

After another disappointing loss in the playoffs for New England, it’s time again to point out the weak link of their lineup: the secondary. Baltimore threw downfield comfortably against a sparse Pats pass rush, getting their receivers open by exploiting the weak coverage skills of New England’s DBs, especially at corner. It’s arguably the biggest reason the Patriots haven’t followed their early-aughts Super Bowl runs with a few more Lombardi Trophies.

You can argue that the Patriots were unlucky to lose Aqib Talib to a hamstring injury within the first five minutes of the game, but they were also lucky to pick him up for a song because of his attitude issues at midseason. Talib eventually became their top cornerback, but there were still roles for the likes of rookie seventh-rounder Alfonzo Dennard and journeyman Kyle Arrington. That’s just not good enough, especially considering how much the Patriots have invested in defensive backs over the past few years in the draft and even in re-signing their own guys to above-market deals (remember the Leigh Bodden fiasco?). The Pats churn their defensive backs over, year after year, and they still can’t find a four-man unit that can hold up in the middle of a Super Bowl run.

The Patriots will rightly want to re-sign Talib next year, as the embattled former Buc is by far the team’s best cover corner, and he’s still young enough to develop into a truly great cornerback. Do they really want to head into 2013 expecting to start Dennard or Arrington? New England has made some moves on the veteran free-agent secondary market in the past, and while some (Tyrone Poole) worked out better than others (Year Two of Tyrone Poole), it gave the Patriots other options while their young players tried to develop into above-average starters. After years of being burned by a group of cornerbacks too young or too middling, it’s time for the Pats to pursue at least one veteran cornerback besides Talib on a short-term deal to compete for playing time, right? Tom Brady hasn’t had a shot at a Super Bowl with two good cornerbacks on the roster since Asante Samuel left town. The Patriots should do their best this offseason to try to get Brady one more shot at the playoffs with an improved secondary.