What will determine the Minnesota Vikings' playoff chances is really simple.
First, Christian Ponder.
The second-year quarterback opened the season slinging 143 passes without an interception. That spanned across the season's first four games.
Since that time, he's thrown eight. Of those eight, six have come over the last four games (the Vikings went 1-3).
The turnovers have accumulated as Ponder's accuracy has fizzled away. Over the past four games, he's completed 57.9 percent of his passes (73-of-126).
What's sad about that number is that Minnesota hasn't opened up its vertical attack. This is the same offense that Ponder thrived in and posted a completion percentage near the league's best.
He's clearly rattled and uncomfortable.
Through nine games, Ponder's thrown for 1,806 yards while completing 64.1 percent of his passes. He's clearly a better player than he was last season, but he's regressed over the previous four games.
He needs to get back to throwing the ball around the line of scrimmage to Percy Harvin. He also needs to get Kyle Rudolph more involved.
The passing game doesn't have any other legit threats.
Minnesota needs its quarterback to return to the state of the first four games of the season. If he doesn't, the playoffs are out of the question.
Minnesota also needs to get its rush defense together.
Over the past four games, the Vikings have allowed an average of 165.8 yards per game. That's downright pathetic and unacceptable. If Minnesota averaged that every game, that would give the Vikings the third-worst rush defense through nine games.
A big reason for the drop off against the run has been the front four's play. Letroy Guion and Kevin Williams have been playing like they're on a skateboard. All offensive linemen have to do is push, and they glide away without a fight.
Far too many runs have gone up the middle for five yards or more. That's also on Jasper Brinkley. The middle linebacker lets himself get taken out of plays too easily.
Jared Allen and Brian Robison, two defensive ends better known for their pass-rushing abilities, aren't off the hook either. Neither has been overly physical the past four games, and they need to get hungry.
Chad Greenway is in on as many plays as he can be, but he isn't making any major plays as he did early. He's making all the expected plays, which is great, but the best players make spectacular plays. That can be expected of him.
Erin Henderson...wow. What a disappointment he's been since returning from a concussion. Prior to the Seattle game, he hadn't recorded over four tackles since September.
Minnesota's pass defense is among the league's top 10, resting happily in ninth (220.3 yards per game). Since the rush defense has gotten torched, the passing unit hasn't had as many attempts against it. Believe me, it will.
With six games against Detroit, Green Bay, Chicago and Houston, there are plenty of aerial assaults waiting to take place. Still, the Vikings pass defense is better than last season, and it should finish the season in the middle of the pack.
The rush defense will improve. There are too many players with run-stuffing abilities on the unit for it to continue the way it has.
Ponder will improve. He can't be this bad the rest of the season. If he is, then Minnesota should look to another quarterback for 2013.
Even if Minnesota's rush defense improves and Ponder gets it together, the playoffs are tough to expect for this crew. Green Bay is surging. Chicago is 7-1. That leaves one NFC playoff spot left. Minnesota is on the outside looking in, as it loses a tiebreaker with the Seattle Seahawks.
Putting a number on it, there's a 40 percent chance the Vikings make the postseason in 2012.