Another big weekend of college football spring games is in the books, and many of college football's best programs took the field on Saturday afternoon.

Defending national champion Alabama, SEC champion Georgia, a potentially threatening Notre Dame squad and Scott Frost's new-look Nebraska were just a few of the big games on the docket.

Here's a look at what we learned heading into the summer:

Notre Dame might be a sneaky contender

I know, I know. People either love or hate Notre Dame, and there is never any opinion in-between. But in the spring game on Saturday, the Fighting Irish showed flashes of brilliance, and the potential to maybe make a push at the College Football Playoff if things start to come together. Quarterback Ian Book came off the bench in the Citrus Bowl to top LSU, and kept that momentum going in their spring game with a great touchdown pass to Chase Claypool.

Does that mean Brandon Wimbush won't be the signal-caller when the Irish open up vs. Michigan? Not necessarily. In fact, Wimbush still leads exiting spring practice.

"You know, that's not etched in stone, but that's the way they have been trending," coach Brian Kelly said after the game. "I don't think there was anything today that changed that, but we know Ian Book can win for us. So it's 1A and 1B."

He had some highs and lows, including a brutal interception and a long touchdown to Miles Boykin. What it does mean is that Book will push Wimbush. That should make both players better and positively impact the Fighting Irish locker room. 

Nebraska's foundation is solid

The Frost era in Lincoln already closely resembles what he orchestrated in two years as the coach at UCF. The power-based, run-pass option attack was a little rough around the edges -- especially when it came to tempo and getting plays in -- but the running game looked solid and there are options at quarterback. Sophomore walk-on Andrew Bunch, redshirt freshman Tristan Gebbia and true freshman Adrian Martinez made proper decisions in the option game, and showed touch and accuracy deep downfield. On top of that, wide receivers Tyjon Lindsey and Jaeon McQuitty look like they're going to be a big problems for opposing defensive coordinators. 

The Cornhuskers are still a work-in-progress, which is fine. But it's clear that a lot of work has already been done, and a run at the Big Ten West title might not be outlandish.

Jeremy Pruitt is the polar opposite of Butch Jones at Tennessee

On the field, Pruitt's Tennessee Volunteers looked solid offensively in their spring game and, at times, even "explosive." Quarterback Jarrett Guarantano went 15-for-27 passing for 226 yards and two touchdowns, including this ridiculous two-yard strike to Marquez Callaway.

Sophomores Tim Jordan and Ty Chandler looked solid in the running game, and Josh Palmer looks like he can be a nice complimentary piece to Callaway. But the even bigger news is that Stanford graduate transfer Keller Chryst and Michigan State graduate transfer running back Madre London are on the way, and star wide receiver Jauan Jennings should be back with the team this summer. Suddenly, the Vols have playmakers.

On top of the Vols looking like a completely different team under Pruitt than they did under former coach Butch Jones, it's clear that Pruitt's personality is too.

It didn't stop with the players, though.

Brutal honesty is a complete 180 from the cliches, trash cans and life championships that Jones touted when he was on Rocky Top. Some fans might like it, others might hate it. But one thing is certain -- it's different than Jones. Isn't that exactly what Pruitt needs to be?

Alabama's defense will be just fine

All eyes were on the quarterback situation in Tuscaloosa, and we covered that in full here. But what got lost in QB-palooza was the fact that Alabama's front seven is still terrifying, and will drive the Crimson Tide again in 2018.

Defensive tackle LaBryan Ray had four tackles for loss, two sacks and generally made life miserable for the Tide offensive line. Fellow defensive linemen Raekwon Davis and Quinnen Willams added two sacks each, as did linebacker Christian Miller. Oh, and let's not forget defensive lineman Isaiah Buggs, who tallied seven tackles, two for loss and one sack.

The first-team Alabama defense looked, well, exactly like what the first-team Alabama defense should look like -- a unit that, regardless of what happens at quarterback, will define the Crimson Tide in 2018.

Or, to put it more bluntly, exactly what it should be.

Penn State didn't show much

Sure, Trace McSorley had a good day throwing the ball, several young members of the Nittany Lions defense made plays, including former five-star prospect Micah Parsons at linebacker (eight tackles) and a heart-warming moment with a Penn State fan with Down Syndrome scoring a touchdown.

But let's be real -- what's most important about the Penn State spring game is what didn't happen. It was vanilla. It was a celebration of all things Penn State that included an appearance by actor Keegan-Michael Key.

That was probably by design. 

Coach James Franklin spoke to CBS Sports leading up to the spring game, and it was clear that a group led by McSorley, running back Miles Sanders and the rest of this crew was ready to roar. Would you tip your hand on live TV knowing that Ohio State coach Urban Meyer's squad played last week and Michigan coach Jim Harbaugh -- who didn't have a spring game due to weather -- were looking on? No way. 

Georgia has a QB issue ... a good QB issue

Justin Fields enrolled at Georgia in January with enough hype to fill Sanford Stadium, and he showed the crowed that the hype was real in that very same stadium in the G-Day game. Fields completed 18-of-33 passes for 207 yards one touchdown and one interception, made smart decisions, threw a tremendous 15-yard score to Matt Landers in the third quarter and looked wise beyond his years. On top of that, with quarterbacks not "live" in the scrimmage, he couldn't show off much of his running ability or specific packages that might already be installed in the offense.

This is not a quarterback battle, it's a quarterback "issue."

Jake Fromm is Georgia's starting quarterback. No, he didn't have the best spring game. Fromm threw two picks (one returned for a touchdown) and wasn't as crisp as he was on big stages like we saw in 2017. But he was playing against the first-team defense, had a sure touchdown dropped one play before throwing the pick-six and wasn't exactly asked to do an awful lot.

Translation: The combination of Fromm being disguised and Fields being unable to run means coach Kirby Smart didn't want anything to get on tape for opposing defensive coordinators to use this offseason.

Tom Herman has a rich man's problem at QB

For one year, Texas coach Tom Herman has had what amounts to a rich man's problem at quarterback.

Shane Buechele is the gamer who committed to the old Charlie Strong regime, and rising sophomore Sam Ehlinger is the dual-threat weapon who stayed committed to the program through the change to Herman and played as a true freshman in 2017.

In the spring game, both proved worthy of playing time. Buechele went 12-of-21 for 131 yards and a touchdown, while Ehlinger went 13-for-22 for 151 yards, with 29 yards on the ground. Is there any clarity in that? Nope. But whoever Herman settles on can handle the roll. Buechele is a gamer who gets the job done despite measurables that aren't typical of a superstar. Ehlinger is versatile and gives the staff options.

There's no wrong answer. It's just a matter of Herman actually giving one...eventually.

LSU still has a quarterback problem

New offensive coordinator, same old issue for LSU. 

Steve Ensminger returned to the offensive coordinator role for the Tigers after previously serving in the same position in an interim role in 2016, and he has a familiar problem on his hands: LSU doesn't have a quarterback.

Sophomore Myles Brennan appeared to be the most composed under center, but made some mistakes including an inexcusable overthrow in the second half that was picked off by John Battle. Despite that, it was clear that he's the guy as of now even though he did not get the "start" in the spring game. Redshirt freshman Lowell Narcisse is rough around the edges, and it showed in the spring game. Junior Justin McMillan made some plays with his arm and legs, and appeared to make up ground on Brennan on Saturday to a point where he was reinserted in the lineup in a two-minute situation late in the game -- likely because coach Ed Orgeron wanted to get a better look at what he can do in as much of a pressure-packed situation that you can create in spring ball.

But are any of them difference-makers? Not yet, although running quarterbacks who are not "live" in scrimmages are handcuffed a bit.

But LSU doesn't have the benefit of the doubt. Not after a decade -- save for Zach Mettenberger's 2013 season -- of quarterback follies.