A few choice results on Sunday have created some much-needed excitement for the NFL’s playoff races as we head into the final quarter of the season. Heading into this weekend, it seemed like the vast majority of the league’s playoff spots had been locked up, with only one wild-card berth in each division really still up for the taking. Losses by the 49ers, Bears, and Ravens on Sunday created some uncertainty atop each of their respective divisions, while wins by the Colts, Steelers, and Seahawks put them on the inside track to those precious few remaining playoff opportunities. That series of upsets served to shake up the playoff picture and finally add some intrigue to the last four weeks of this regular season.

After Monday night, each of the playoff contenders will have just four games left. You can safely discard 13 of the league’s 32 teams already, which leaves 19 teams to compete for 12 playoff spots. There aren’t very many matchups over the final four weeks of the year that involve those 19 teams in encounters that could make an enormous difference in the playoff picture, but there are a number of huge games over the next month that should have a disproportionately large impact on who goes where in January. In several cases, those big matchups only crystallized after Sunday’s upsets.

Which games are they? Well, for one, the game with the most marquee value over the final four weeks of the year isn’t one of them. The Texans-Patriots game next Monday night should be wildly entertaining, but it’s probably not going to be a deciding game for the no. 1 seed. Even if the Patriots pull out the game, the Texans would still have a one-game lead on the Patriots with three games to go. Houston’s season-ending schedule isn’t exactly easy, with a home game against the Vikings sandwiched between two games against the Colts, but the Patriots still have to play the 49ers (at home) and then finish the season by hosting the pesky Dolphins. The Texans would still be reasonably large favorites to win the top seed, and if they beat the Patriots, they’ll have a two-game lead and the tiebreaker edge over the Broncos, Patriots, and Ravens with three games to go, virtually ensuring that they’ll win the conference.

Although future results could alter the impact of a given game, here are your most important matchups for the remaining four weeks of the NFL season:

Giants at Redskins, tonight. You’re probably already aware of the implications of this one. If the Giants win, they’re 8-4 and have a two-game lead on the 6-6 Cowboys with four games to go and no obvious enormous tiebreaker advantage. The Redskins were a 3-6 team losing a crummy game to the Panthers before their bye one month ago; now they’re a win away from having a serious shot at claiming the NFC East. If they win on Monday night, they would be one game behind the Giants with a tiebreaker advantage in terms of divisional record, since they would be 3-1 in the NFC East and the Giants would be 2-3.

Two games to go with four left isn’t a terrible situation, right? Well, consider what the Giants have to look forward to over these final four weeks. They host the Saints, travel to Atlanta and Baltimore, and finish at home against the Eagles in the final game of the Andy Reid/Michael Vick era. The Redskins get a friendlier slate: They host the Ravens, travel to Cleveland and Philadelphia (where they’ll play the final home game of the Reid era, which could end up being the first game in league history in which every single play, regardless of who succeeds on it, is booed unmercifully), and then finish at home against the Cowboys, who have a 3-2 divisional record with the Bengals, Steelers, and Saints still to come before that final game in D.C. If the Redskins win tomorrow, that Week 17 game becomes enormous as a situation in which the Redskins could host the Cowboys with a chance to control their own destiny and win the division. But first, they have to win on Monday.

Packers at Bears, Week 15. If you’re planning a Sunday away from football, next weekend is the time to do it, since nary a single one of the 14 games this upcoming Sunday has two teams above .500 squaring off versus one another. The excitement comes back in Week 15 with a game that just became very crucial to the Bears, who just blew their two-game lead in the NFC North with three losses in four weeks. Now, at 8-4, there are bad rumblings on the horizon for the Bears. If they don’t win the division, they’re likely going to rue losing to Seattle on Sunday, since the Seahawks would hold a tiebreaker over Chicago. That could be enough to bump Chicago all the way down to the sixth seed, which means that this Packers game could be the difference between having a bye and hosting a playoff game or going on the road to face either the Giants or the 49ers in the wild-card round, with the Falcons waiting in Atlanta for them after that. That is not a path the Bears want to go on.

Take this a step further now. If the Bears were to lose to the Vikings in Minnesota this coming Sunday, they would be one game ahead of the Vikings with an inferior divisional record and three games to go. The Vikings still have to travel to Houston and St. Louis, but they also get to host the Packers in Week 17 in a game where Green Bay might have nothing to play for and could throw their backups out for three quarters. If the Vikings go 3-1 and lose to the Texans, and the Bears lose to the Vikings and Packers, the Bears will need to win road games against Arizona and Detroit over the final two weeks to make it into the playoffs. That would push the Vikings in, or it could create a space for

Buccaneers at Saints, Week 15. Tampa Bay, who still have a reasonable shot at making their way into the dance, even after losing to the Broncos on Sunday. Tampa holds the tiebreaker over Minnesota, so if the Bears, Vikings, and Bucs all end up at 9-7 under the scenario I just mentioned, Greg Schiano’s team would get in. In addition to this NFC South tilt, the Buccaneers host the Eagles and Rams and have that Week 17 game against a Falcons team that will likely be taking the day off. Their schedule over this four-game stretch is very generous, and while they’re on a two-game losing streak, those have been competitive losses to two very good teams in Atlanta and Denver. Tampa might not make it into the playoffs, but I’m sure that they’re one of the six best teams in the conference.

The Saints, of course, would need a lot of things to go right to make it into the playoffs. They need to win out, including this game, and get a bit of help to qualify as a 9-7 team. They can’t end up in a tiebreaker with the Redskins, who stomped them in Week 1, but they would qualify over the Buccaneers if both finished 9-7. With road trips to New York and Dallas still to come, New Orleans’s time is probably up.

49ers at Seahawks, Week 16. San Francisco’s sitting pretty atop the NFC West, right? A lock to win their division? Well, after Sunday, not so fast. At 8-3-1, the Niners are only 1.5 games ahead of the 7-5 Seahawks with a game to play, and that game crucially comes for the Seahawks in Seattle on December 23. If Seattle wins there, they would be within a half game of the Niners, pending the results of their other three games.

That’s where Seattle gets a lot of help. They finish with arguably the easiest schedule for a contender in the league: They host the Cardinals, 49ers, and Rams, and then play Buffalo in Toronto. The 49ers also host the Cardinals and Dolphins, but their other game sees them travel to New England to play the Patriots. Here’s the stunning part: If the 49ers lose to the Seahawks in Seattle and the Patriots in New England, the Seahawks control their own destiny. With wins over the Bills, Cardinals, and Rams, they would finish 11-5, and since the Niners can’t do any better than 10-5-1 in that scenario, the Seahawks would win the NFC West. Then again, if the Niners do lose to the Patriots in Week 15, their defense — the one that has allowed an average of 3.4 points per game after losses under Jim Harbaugh — would probably be pretty angry in Week 16. The 49ers are still the favorites, but this one is far from done.

Bengals at Steelers, Week 16. Finally, in the relatively settled AFC, here’s a clash for the final playoff berth! The Bengals would have been very well positioned had the Steelers lost to the Ravens this past Sunday, but a Steelers win keeps them in lockstep with Cincinnati, one game behind the Colts in the wild-card race. An Indianapolis collapse (driven by their home-and-home with Houston) would create an opportunity for both the Bengals and the Steelers to get in and make this a seeding game as opposed to a virtual playoff contest, but it’s unquestionably the biggest game left in the AFC this season.

Want to look ahead and envision something grander? Well, at the moment, both the Steelers and Bengals are two games behind the Ravens in the AFC North, and the Bengals still have a game to play against Baltimore. Baltimore has a very tough schedule to go, with the Redskins, Broncos, Giants, and Bengals still to come for their injury-riddled mix of talent. Of the two, Pittsburgh has an easier path to the division title. They have a more comfortable schedule that features the Chargers, Cowboys, and Browns, while the Bengals have to do it against the Cowboys, Eagles, and Ravens. The Bengals will lose any tiebreaker with the Ravens because they are a mere 1-3 in AFC North games, while the Ravens are 4-1 and the Steelers are 2-2. In the end, the Ravens probably win the division, and this game is a de facto playoff contest, which will be rather fun.

Cheap Shots Earn Riches

When Jim Schwartz infamously threw his challenge flag prematurely last week and gave the Texans a free touchdown, many of you tweeted to me that the play offered up an opportunity for some of the league’s more clever coaches. The logic inferred that the team that scores on a questionable play like the one in the Texans-Lions game should immediately throw its challenge flag onto the field, which would incur a 15-yard penalty while removing the official review from the equation, the way it did for Schwartz’s flag. I don’t know that the league’s officials would interpret the play properly, but there’s at least some logic to the loophole exploitation being planned.

Of course, finding loopholes in the rules is an unsavory but meaningful way to derive value in your decision making, which is something that comes up in this space every week. There are a few specific contexts in which players in the league can take advantage of the rules and create an opportunity for themselves that already exist on the books and aren’t going away anytime soon. One obvious such play is the “free play” that comes on an offsides penalty that isn’t whistled dead by the referees.

One of the less savory plays comes when you can commit a penalty to prevent a touchdown from occurring without giving up significant yardage in the process. Sunday saw such an example in the Patriots-Dolphins game. There, Aaron Hernandez was streaking down the sideline to the end zone when Miami defensive back Chris Clemons needed a way to drag him down. Desperately, Clemons reached out for his face mask and pulled Hernandez down at the 4-yard line, saving a touchdown for his team in the process. That penalty only cost his team half the distance to the goal line, which moved the ball from Miami’s 4-yard line to its 2-yard line, a relatively tiny difference on first down. The Dolphins sacked Tom Brady on first down and then held on second and third down, forcing the Patriots to kick a field goal. The game finished 23-16, so the Dolphins ended up covering the 7.5-point spread, meaning that Clemons’s clearly illegal play not only saved his team four points, it swung millions of dollars in bets.

Now, I don’t think that Clemons’s penalty was inherently egregious. If I shift the context for the play just a tiny bit, you can see how dangerous the value proposition is here. Clemons might have been able to push Hernandez out of bounds, so let’s instead imagine a situation in which a receiver has a clear path to the end zone and is being chased down by a trailing defensive back. And now, instead of a face mask, let’s say that the defender grabs the receiver and drags him down with a horse collar, saving a touchdown and breaking the receiver’s leg in the process. He’s committed a serious infraction, severely injured a player, and saved his team a touchdown at the cost of two yards of field position and a small fine (which players can write off on their taxes anyway). Cowboys tackle Tyron Smith did all of that (minus the injury) on an interception return in Week 1, saved his team four points in a game that was decided by one score, and ended up getting praised by his coach while getting fined a mere $15,750.

What can the league do to prevent that sort of thing from happening? Well, there’s no really easy way to police it without making some sort of drastic rule change. They could automatically award a touchdown on a play where a defender drags a receiver down from behind with an illegal hit, but that would be a dramatic change to the game. They could enforce the 15-yard penalty on the tackling team’s next drive, but that would also be a rule that would be inconsistent with how penalties work elsewhere. Instead, the league would probably have to up the punishment for committing such a cynical foul. Soccer referees are supposed to give a red card to a player who commits a foul that denies an obvious goal-scoring opportunity, including plays very similar to the one I described above. Soccer ejects players who commit such fouls, and it would make sense for the NFL to deter such illegal hits by doing the same.

The league rulebook will never be foolproof and beyond reproach. Cunning coaches will always find ways to exploit pen and paper, but the league needs to seal those loopholes before they materially impact a game. Fixing the Schwartz Rule is obviously on the docket for 2012, but the league might want to take care of the virtually free illegal hit inside the 5-yard line, too, before somebody gets hurt.

Kaeping Time

Although several games around the league (notably Dallas-Philadelphia) saw teams gifted points when the opposing team mismanaged the clock on offense late in a half and handed the ball over too early, nowhere did that matter more than in St. Louis, where Colin Kaepernick made an ill-fated move that ended up costing the 49ers the game.

After some miscommunication on a Kaepernick pitch led to a fumble and a defensive touchdown for the Rams, they promptly tied the game up at 10-all with a two-point conversion. Kaepernick responded with a dazzling 50-yard run to set the Niners up deep in St. Louis territory with 1:54 and two timeouts left for the Rams. With the ball on the 14-yard line, the Niners simply needed to run the clock, force the Rams to use their final timeouts, and then kick a lead-taking field goal with as little time left on the clock as possible. Instead, things went south fast for the Niners: They threw the ball for two yards, committed a holding penalty, and then ran for -1 yards on second down, setting up a third-and-21 from the St. Louis 25-yard line.

Wanting to set up a slightly shorter field goal with little risk, the 49ers snapped the ball to Kaepernick and had him run a sweep out of the backfield. With 1:44 left, Kaepernick could move the ball to the hashmark of David Akers’s choosing while forcing the Rams to either use their last timeout or burn 40 seconds off the clock. All he had to do was stay inbounds but Kaepernick ended up going out of bounds on the play, extending the game clock while taking just six seconds off. Akers pushed a 32-yarder through, but it wasn’t of much consolation a minute later.

Those extra 35 seconds and that free timeout came in handy for the Rams, who promptly drove the ball 45 yards in 73 seconds to set up a 53-yard field goal for Greg Zuerlein. Zuerlein converted the kick, and the Rams eventually won in overtime. If Kaepernick merely stays inbounds, the Rams probably don’t have the time for a drive and end up attempting a more difficult field goal or resorting to a Hail Mary. Instead, Kaepernick’s inexperience opened up a window that the Rams hit. It’s certainly nowhere near as bad as Marion Barber’s decision to go out of bounds against the Broncos last year, but it’s enough to dramatically decrease San Francisco’s chances of victory in a game where they were the better team.

One Final Note

It’s impossible to talk about this weekend without noting the pall surrounding the games that came after the tragic murder-suicide that took place in Kansas City on Saturday. My thoughts go out to the families of Jovan Belcher and Kasandra Perkins, as well as the broader Chiefs organization. I can’t imagine how difficult it must have been for Romeo Crennel and Gary Gibbs to prepare for Sunday’s game given the circumstances, and it’s remarkable that the Chiefs were able to show up and play, let alone claim their second win of the season over the Panthers. My sympathies also go out to the Cleveland Browns organization, where a member of the team’s grounds crew committed suicide at the team facility Saturday morning.

I don’t think I’m qualified or that it’s appropriate to speculate as to what happened with Jovan Belcher on Saturday morning, but there is something I would like to say that admittedly doesn’t fit the pithy tone of a silly column about a game. Nobody should have to go through the grief that the friends and family who loved these three people are dealing with right now. If you find yourself in a desperate situation, please, please, please seek help before you do something drastic. There are so many people and so many institutions dedicated to helping you make it through seemingly impossible situations, and many of them are a phone call away. Millions of people, including me, have been helped through bleak periods of depression by those outlets. I can’t speak to what ailed Jovan Belcher, Kasandra Perkins, and their relationship, and what caused that member of the Browns organization to take his life this weekend. I know that they deserved longer, happier lives, and I hope that the next member of the league’s community who struggles with these same issues gets the help that he or she deserves.