The what if's are what make the NFL draft fascinating. But the touchstones in each class are what define the entire group.

Nobody saw Brock Purdy emerging as a franchise quarterback from the worst quarterback class in 25 years. In the same year, Kyle Hamilton entered the NFL as one of the most highly regarded safety prospects in some time. So, it comes as no surprise that he's already an All-Pro player.

All of the possibilities that present themselves throughout a draft class are too numerous to name and make the Marvel multiverse look tame in comparison. But there are certain factors in each class that border on certainties.

To be clear, there are no surefire prospects in any draft. However, there are those whose very presence drastically alter the entire event. When everyone looks back in five years to see how the class is progressing, they're the first names that will be discussed—good or bad.

With less than a week before the Chicago Bears go on the clock with the first overall pick, six specific cases can be found within the 2024 class.

USC QB Caleb Williams Goes No. 1 Overall

The projected No. 1 overall pick is the figurehead of any draft class.

If a team selects the wrong prospect at the start of the event (*cough*CarolinaPanthers*cough), how the rest of the incoming crop will be viewed differently. But the right choice can change a franchise's direction and ultimately shift the NFL landscape (see: Joe Burrow or Eli Manning).

USC's Caleb Williams is the consensus favorite to be selected by the Chicago Bears once this year's draft officially opens for business.

"Caleb is clearly No. 1. There's always a bust percentage," an AFC assistant coach told NFL Network's Tom Pelissero. "But the talent level is as good as I've ever seen."

As for the last point, the natural elasticity in Williams' arm and natural play-making skills are truly elite. But he's not quite on the level of an Andrew Luck or possibly even Trevor Lawrence as an all-around prospect.

Still, everyone around the league believes the Bears will take Williams and see the potential he presents.

After three years of Justin Fields never fully clicking for numerous reasons, Chicago is resetting the board, with an opportunity to finally compete at a postseason level because the quarterback position has been upgraded.

The Bears weren't supposed to have this particular selection. They do because of last year's Bryce Young deal. In doing so, the NFC, as a whole, will be significantly different.

Trade Up for Michigan QB J.J. McCarthy

The biggest question of this year's draft is which organization is going to pull the trigger on a big draft-day trade to acquire a top quarterback prospect.

As of now, expectations still revolve around Caleb Williams, LSU's Jayden Daniels and North Carolina's Drake Maye coming off the board with the first three picks. If that comes to pass, Michigan's J.J. McCarthy then becomes the hot ticket item, with the Arizona Cardinals and/or the Los Angeles Chargers being prime trade-up destinations.

The New York Giants, Minnesota Vikings, Denver Broncos and Las Vegas Raiders are all potentially in play to make a move. McCarthy is the logical target somewhere in the back end of the top five.

'He's by far the most pro-readymade QB because of him being with (Jim) Harbaugh, being in a pro-style system, operating under center, communicating the play call," an NFC assistant coach told Pelissero. "He crushed the combine interview. It was easy. Super smart. Communicates well. Super calm demeanor. Quiet confidence almost. His pro day was probably the best of all the QBs."

Significant questions still exist regarding McCarthy's skill set. He operated in a run-first offense, with fantastic talent around him. Evaluators question his build, overall arm talent and accuracy.

But the 21-year-old prospect has the mentality to immediately lead a squad. In a QB-driven league, that's enough to push his stock higher than the film evaluation would.

In this particular example, it's less about the individual and more about which franchise spends big to bring him into the fold. The draft will reach its first inflection point upon a trade-up being completed.

Ohio State WR Marvin Harrison Jr. Is Class' Top Prospect

An earlier point centered on the No. 1 overall pick being the tone-setter for an entire draft class. What if the top pick and the class' top overall talent aren't one-in-the-same?

For 2024, Ohio State wide receiver Marvin Harrison Jr. is Bleacher Report's highest-rated prospect and he carries a grade as high or higher than any other individual over the last four classes.

He's a 6'3", 209-pound talent with unbelievable fluidity, footwork, route-running and ball skills for a bigger target. His Hall of Fame bloodlines only make his case even stronger.

Harrison is not a quarterback, though.

As such, the reigning Biletnikoff Award winner has never been seriously considered an option at the top of the draft. Instead, he's often projected to the Arizona Cardinals with the fourth overall pick or even "falling" to the Los Angeles Chargers at No. 5 if the Cards trade out of the four hole to a quarterback-needy organization.

What makes his landing spot so fascinating is that it'll be constantly compared to every other wide receiver in the class.

While Harrison is generally considered WR1, some arguments have been made in favor of LSU's Malik Nabers and Rome Odunze. Even taking those into account, Harrison is the closest thing to a "generational talent" among the incoming crop. He is arguably the best wide receiver prospect since Calvin Johnson entered the professional ranks in 2007.

Harrison doesn't set the bar for every other non-quarterback in the class. He is the bar.

Wherever Georgia TE Brock Bowers Lands

Like Marvin Harrison Jr., Georgia tight end Brock Bowers borders on the edge of "generational talent." It's not a term used lightly, either.

As such, class-defining talent can't be overlooked regardless of position.

Harrison may make a better case than Bowers to reach such lofty status, since Kyle Pitts entered the NFL ranks three years ago with an unmatchable athletic profile. Otherwise, Bowers has the best resume ever for a tight end prospect.

The incoming talent is a two-time national champion, first-team All-American and John Mackey Award winner. He leaves Georgia as the Bulldogs' fifth all-time leading receiver, despite being a tight end and only being on campus for three seasons.

Bowers walked onto a college football field and immediately took the nation by storm. He's a offensive weapon because of his ability to create mismatches and yardage after the catch. That's exactly how he should be viewed once drafted.

However, positional value will almost certainly affect Bowers' slotting. His range likely falls somewhere between the ninth and 15th overall picks. Whoever selects the tight end will do so knowing his rookie deal will automatically rank among the top-10 guaranteed money for the position. It shouldn't matter.

Bowers is a difference-maker. He's as much of a threat as all of the top wide receivers. He'll just be utilized a little differently but can still be viewed as a unit's No. 1 target.

Texas' Byron Murphy II Finds Himself In Top 10

The incoming draft class is offense-heavy at the top.

As established, the expectation is for three quarterbacks to come off the board with the first three picks. A fourth could then be had with the fourth or fifth. Wide receivers Marvin Harrison Jr., Malik Nabers and Rome Odunze are all expected to be top-10 picks. Notre Dame offensive tackle Joe Alt is a lock somewhere within the initial 10 selections. Maybe tight end Brock Bowers slips into that mix as well.

Nine offensive are very strong possibilities to hear their names called early and often. What about the defense?

Names such as Toledo cornerback Quinyon Mitchell or Alabama edge-rusher Dallas Turner or cornerback Terrion Arnold could be the first defender off the board. But a late surge is coming from Texas defensive tackle Byron Murphy II.

As the defensive tackle market explodes in the NFL, Murphy's chances of being the first defender selected seems to grow with each passing hour. Organizations understand the value of a player who can consistently collapse the pocket.

Over the last three seasons, Murphy led all defensive tackles in pass-rush grade, per Pro Football Focus. His pressure percentage over expected easily ranked last season, according to Sports Info Solutions.

Edge-rusher have always been considered the premium position. But it's far more difficult to find a true difference-maker along the interior. The likes of Aaron Donald and Chris Jones changed the game. Murphy's projected slotting will be a direct reflection of the evolving league and how this class' defensive crop will be perceived.

Washington QB Michael Penix Jr. is NFL Draft's Wild Card

Not every franchise desperately searching for a top quarterback prospect will initially find one.

Beyond the top four options, teams left out in the cold will be looking at the possibility of drafting Washington's Michael Penix Jr. or Oregon's Bo Nix. Of the two, more variance seems to exist on Penix's evaluation, with some loving his profile and others being wary.

"The second-best quarterback in the draft, just as a pure film evaluation, is Michael Penix," an AFC assistant coach told Pelissero. "... I think he's got the biggest 'it' factor. He stands in the pocket and makes throws consistently. He took Indiana, they were (ranked) in the top 10. He took Washington to the national championship game. To me, he's the guy. He plays with a ton of confidence. His guys love him."

Conversely, others simply see flaws.

"Unless he's throwing the ball outside the f---ing numbers, it's getting batted down," an AFC executive said. "He throws it on a f---ing rope every f---ing time. He's thrown a deep ball -- I've seen that, all right, great. He's got that f---ed up motion. He's got zero touch."

What can't be denied is how productive Penix has been the last two seasons and how well he spins the ball. While an extensive injury history and some concerns with his game exist, a team is likely going to swing for the fences in hopes that the lefty's upside is more than enough to be cultivated into a franchise quarterback.

How they go about acquiring his services will be interesting, though. Maybe an organization outright selects him in the top half of the first round or another trades up later in frame. Whatever the case, Penix is the quarterback prospect some love and others can't stand, which makes his eventual selection fascinating.