By Ralph Russo/AP

When Alabama trailed by 21 on Saturday it looked as if college football could be heading for a total reset weekend, when poll voters just trash the whole thing and start from scratch.

Not quite. The Crimson Tide rallied and in the end it was only Louisville that truly entered the national title conversation. Though a few teams did leave it — likely for good.

The Cardinals, along with Ohio State, gave the AP Top 25 voters some things to consider at the top and bottom of the rankings this week, and a heat check will tell us how they did.

No. 1 Alabama (3-0)

A case could be made for dropping the Crimson Tide from the top spot. Then you remember four national titles in seven seasons and Nick Saban’s team gets the benefit of the doubt.

Next: Kent State

Heat check: Just right.

No. 2 Ohio State (3-0)

It’s hard to replicate the edge a team plays with when it has something prove. All of Urban Meyers’ national title teams had that. Oh, and a mountain of talent. These Buckeyes check both boxes.

Next: Rutgers, Oct. 1

Heat check: Just a touch too hot.

No. 3 Louisville (3-0)

So what do you like better? Ohio State’s impressive road win at Oklahoma or Louisville’s historic blowout of Florida State? The heat check takes the latter — and Lamar Jackson.

Next: at Marshall

Heat check: Too cold.

No. 4 Michigan (3-0)

Quarterback Wilton Speight’s performance in the first game facing something resembling real competition was just shaky enough to elicit a bit of concern in Ann Arbor.

Next: Penn State

Heat check: Too hot.

No. 5 Clemson (3-0)

Safe to assume the Tigers were preparing for the Yellow Jackets’ triple-option in the lead up to South Carolina State last week. Still, this game has pain in the neck written all over it if Deshaun Watson and the offense are still searching for their comfort zone.

Next: at Georgia Tech, Thursday.

Heat check: Too hot.

No. 6 Houston (3-0)

The Cougars can tell Clemson all about how weird Thursday night road games can be. And how to win them.

Next: at Texas State

Heat check: Too cold.

No. 7 Stanford (2-0)

A second straight prime-time slot is coming for Christian McCaffrey to try to keep pace with Louisville’s Action Jackson in the Heisman Trophy race.

Next: at UCLA

Heat check: Just right.

No. 8 Michigan State (2-0)

If fan bases were ranked on their contentedness with the current state of the programs for which they root, Michigan State fans would make a good case for No. 1. A constant state of exceeded expectations.

Next: vs. No. 11 Wisconsin

Heat check: Just right.

No. 9 Washington (3-0)

Welcome to the 2016 season, Huskies.

Next: at Arizona

Heat check: Too hot.

No. 10 Texas A&M (3-0)

Who needs all those five-star quarterback recruits when you have Trevor Knight?

Next: vs. No. 17 Arkansas at Arlington, Texas

Heat check: Just right.

No. 11. Wisconsin (3-0)

Hard to get a read on the Badgers in part because LSU still seems dysfunctional. Just how good was the victory in Lambeau Field? One way or another, the Badgers will be defined over the next few weeks.

Next: at No. 8 Michigan State

Heat check: Too hot.

No. 12 Georgia (3-0)

Another team that makes heat check go, hmmm. But unbeaten with Jacob Eason’s upside is not a bad place for Kirby Smart to be in his first season.

Next: at No. 23 Mississippi

Heat check: Too hot.

No. 13 Florida State (2-1)

The greatest test of a coach is how his team comes back after a dismal effort in a huge game. The Seminoles can’t be sulking when they show up at USF on Saturday.

Next: at South Florida

Heat check: Pass. Florida State is too good to be that bad. Heat check will reassess in a week.

No. 14 Tennessee (3-0)

The Vols have played their best game against their best opponent, which bodes well for this week. Right?

Next: No. 19 Florida

Heat check: Too hot.

No. 15 Miami (3-0)

Remember the Hurricanes’ run defense last year? Of course not — they didn’t play any. Even against so-so competition overall so far, the improvement (1.57 yards per carry allowed) is notable.

Next: at Georgia Tech, Oct. 1

Heat check: Too cold. Flip-flop Miami and Tennessee based on App State results.

No. 16 Baylor (3-0)

Welcome to the 2016 season, Bears.

Next: Oklahoma State

Heat check: Too hot.

No. 17 Arkansas (3-0)

The last time the Razorbacks started 4-0 was 2003.

Next: No. 10 Texas A&M

Heat check: Too cold.

No. 18 LSU (2-1)

It feels as if every week the sky is about to fall on the Tigers. Fortunately for them Leonard Fournette can hold it up.

Next: at Auburn

Heat check: Just right

No. 19 Florida (3-0)

The Gators, as LSU has done, will turn to a Purdue transfer quarterback at a crucial part of their season. Who knew Boilermakers coach Darrell Hazell would have this much impact on the SEC.

Next: at No. 14 Tennessee

Heat check: Just right.

No. 20 Nebraska (3-0)

The schedule sets up for the Cornhuskers to keep the good times rolling for at least a few more weeks, but its games like these that have ruined recent seasons.

Next: at Northwestern

Heat check: Just right.

No. 21 Texas (2-1)

So now the Longhorns’ offense is humming but they can’t stop anybody. And just like that we’re talking about Charlie Strong’s job status again.

Next: at Oklahoma State, Oct. 1

Heat check: Too hot.

No. 22 San Diego State (3-0)

Only Alabama has won more consecutive games than the Aztecs have with 13 straight.

Next: at South Alabama, Oct. 1

Heat check: Too cold.

No. 23 Mississippi (1-2)

If you think Florida State and Alabama are really good, then keeping the Rebels in the rankings makes sense. Though at some point Ole Miss must defeat one of these good teams to stay ranked.

Next: No. 12 Georgia

Heat check: A touch too cold.

No. 24 Utah (3-0)

One of those teams that always seems to have to prove it before voters jump on board.

Next: USC

Heat check: Too cold.

No. 25 Oklahoma (1-2)

If you think Houston and Ohio State are really good, then keeping the Sooners in the rankings makes sense. But just like the Rebels, nice try only goes so far.

Next: at TCU, Oct. 1

Heat check: Just right.