The end of October is when things really heat up in the college football season.
Some teams that were secure in their spots have to start watching their back because other contenders have made strong pushes, while others are just trying to stop from collapsing.
No team and no lead is safe at this point.There's still the "anything can happen" feel, but it's shrinking with every Saturday.
Conference matchups get more intense heading into November, and some teams have to make sure they don't have a letdown and ruin an entire season's work of preparation and hard work.
Here are five college football teams that have to watch their back.
Kansas State has to watch their back because although they got the coveted No. 2 ranking this week, there are two very talented, very hungry, very deserving undefeated teams waiting right behind them.
This week, the Wildcats are playing an underrated Oklahoma State team that isn't as dynamic as last year's squad, which featured Brandon Weeden and Justin Blackmon, but they are still 5-2 and have a lot of talent.
I expect Bill Snyder to have his team ready to play, but they are under a lot of pressure. Collin Klein is going to have to continue his dominance for KSU to stay in the championship hunt.
Louisville is still undefeated and has inched their way into the Top 10, which is a milestone achievement for the program.
But with their relatively weak Big East schedule, Louisville is going to have to stay undefeated to remain relevant.
If they drop one of their remaining games, they'll fall quickly.
They play a solid Temple team this week and still have matchups against Syracuse, UConn and Rutgers, so the Cardinals will have to stay on top of their game or risk sliding a lot.
West Virginia is currently ranked No. 21 and has another tough matchup against TCU this week. Real question to think about here: If West Virginia loses this game, would it be the biggest collapse in college football history?
Just a few weeks ago, they were considered front-runners for the Big 12 championship and legitimate contenders for the national championship.
People were pretty much ready to hand over the Heisman to Geno Smith.
Now after dropping two straight games, they are out of the Top 20 and have games remaining against TCU, OK State and Oklahoma.
Things are not looking good for the Mountaineers.
USC was overrated, as they so often are, at the beginning of this season. But even still, most people were shocked when they lost to Arizona last week.
That loss eliminated any chance of them making a push for the national championship, and now the Trojans are fighting just to save their season.
They don't have to watch their backs for the national rankings anymore, at this point they've gotta be focused on the Pac-12 and not losing another game, which will be difficult considering they're facing Oregon this week.
Arizona is ranked No. 22 and gunning for USC's spot.
That's not good for Matt Barkley and the Trojans.
Alabama, Kansas State, Oregon and Notre Dame are the remaining undefeated teams vying for their chance to play for the national championship.
It seems like everyone is talking more about if the latter three will play Alabama, but I think Alabama actually has a lot to worry about.
They face LSU this Saturday and then have a matchup against a dangerous Texas A&M squad. I wouldn't put money against the Crimson Tide, but it's definitely not a given that they'll still be undefeated after those two matchups.
Nick Saban has three very good teams right behind him just waiting to take the No. 1 spot. It's very much a four-team race, nothing is even close to settled yet.
Alabama can't forget that.