Every Top 25 team has its flaws, and Week 4's early contests pointed out weak spots for a few talented teams.
There's still plenty of time to improve these areas, but conference play is coming quickly. Most schedules will become more difficult, and off-weeks do not exist.
Let's focus on Ohio State, West Virginia and Texas Christian. All three programs earned a victory on Saturday, with a few eyebrow-raising concerns popping up in the process.
Ohio State Buckeyes
Red Flag: Discipline on Defense
Ohio State struggled to stop California in Week 3, allowing over 500 total yards to the Golden Bears. Alabama-Birmingham was not supposed to do the same thing in Week 4, but the results weren't much better for Urban Meyer's crew.
UAB racked up 403 yards and made things very difficult for the Buckeyes. Ohio State displayed poor tackling, inconsistent spacing and played shoddy defense as a whole for most of the game.
It has to stop, especially with Michigan State and Nebraska waiting as their next two opponents. The Blazers took advantage of missed tackles, and more talented opponents will make that look minor.
Meyer's crew has to figure a few things out before they enter the heart of their schedule. Talent is commonplace on their defensive unit, but the results have not been there.
Until they do, expect the Buckeyes to be on upset watch.
West Virginia Mountaineers
Red Flag: Stopping the Big Play
This isn't a surprise, but it's still a problem. If the Mountaineers win games, it's going to be courtesy of their offense.
Dynamic attack or not, West Virginia's defense will have to step up at some point. Maryland's young squad tested them on Saturday, and they surrendered a fair amount of big plays.
West Virginia shut down the run game, but they allowed nearly nine yards per pass. Terrapins freshman Perry Hills went 20-of-29 for 305 yards and three touchdowns. He did throw one interception, but he handled the Mountaineer defense with relative ease.
This was West Virginia's last game before their Big 12 schedule. Their future opponents won't be as forgiving, and defense like this won't suffice.
No one will argue with Dana Holgorsen's dynamic system. Defensively, they give up too many big plays for their own good. Ask Stefon Diggs.
TCU Horned Frogs
Red Flag: Penalties
TCU earned a big victory over Virginia on Saturday, but penalties made it more difficult than it had to be.
The Horned Frogs committed 12 penalties to the tune of 103 yards. Blame the referees, but the players have to adjust at some point. There's simply no reason to pick up that many infractions.
TCU's schedule doesn't get too difficult until the final four weeks of the season. Discipline must be instilled before then, and simple mistakes have to become less frequent.
Casey Pachall and the Horned Frogs' skill players make this team dangerous; shooting themselves in the foot does not.
Defeating the Cavaliers is a solid victory, but this has to change.