CHARLOTTE, N.C. — JJ Traynor wouldn't have believed you.

Four years ago, if you had told the 6-foot-8 Bardstown native when he committed to the Louisville men's basketball team he would attend ACC Tipoff on Wednesday as the last senior standing from U of L's 2020 recruiting class — playing for Kenny Payne, not Chris Mack — it would have sounded as far-fetched as the Cardinals spiraling from 24 wins during the 2019-20 season to a school-record 28 losses in 2022-23.

"It's been a roller coaster, for sure," Traynor said.

That's life in the NCAA transfer portal era.

More than 1,800 Division I men's basketball players entered the portal during the offseason, according to one report from mid-August. It, coupled with an extra year of eligibility granted to athletes whose careers were impacted by the COVID-19 pandemic, has made college hoops an old(er) man's game.

See the 2023 Final Four field for proof.

Each team had an experience rating of 2.09 or better on KenPom.com, which assigns players numerical values (zero for freshmen, one for sophomores, two for juniors, etc.) based on how many years they've clocked 10% or more of their team's minutes. When UConn (2.25) and San Diego State (2.96) tipped off in the national championship game, there was just one freshman on the court.

The portal made it possible by giving coaches the ability to inject experience into their rotations.

Then, there's Louisville, with its eight newcomers, five of whom haven't played against DI competition, and Traynor as its lone senior heading into 2023-24.

U of L (1.32) ranks 12th out of 15 ACC teams in statistician Bart Torvik's projected effective experience metric, which differs from KenPom in that it counts years not by minutes but by players logging appearances in 10 or more games. This after Payne often lamented a lack of it during the worst season in modern program history — U of L was 336th out of 363 DI programs on KenPom with an experience rating of 0.90 — then had four upperclassmen hit the portal.

The second-year head coach stuck by his process Wednesday at ACC Tipoff; while the players he brought with him, Traynor and redshirt sophomore Mike James, said age won't define this team's maturity.

"We had a lot of guys who just weren't ready (last season), including myself," Traynor said. "This year, I feel like we're more ready, and we're just a better team. We've got a chip on our shoulder; we hear what everybody else is saying; we see how we look from the outside; and we just want to change that narrative."

Preseason ACC poll: Louisville basketball ranked 14th heading into Year 2 under Kenny Payne

Payne has described the portal as a "microwave type of situation." It can generate instant success, but there's no guarantee the results will carry over into the long haul.

"I would rather build a program and do it the right way and get young people to have a good mixture of veteran guys so that you have some stability — not just for a year but over time, year after year, and do it the right way," he told CBS Sports' Jon Rothstein over the summer.

It's not like Payne avoided the portal entirely. He pulled from it three sophomores, point guard Skyy Clark (Illinois), guard/forward Tre White (Southern California) and forward Danilo Jovanovich (Miami), from teams that reached the NCAA Tournament. Torvik projects White will lead the team in scoring with 14.4 points per game while Clark chips in 10.3 to go along with 2.8 assists per contest.

But the trio brings to the Cards only 43 games' worth of experience. White, a member the Pac-12 All-Freshman team last season, accounts for 26 of its 38 starts.

Clark played in the Fighting Illini's first 13 games, starting 12, before stepping away from the team to help tend to his father, who was battling diabetes complications. Jovanovich saw two minutes of game action for the Hurricanes, then opted to redshirt because of injuries; although his former head coach, Jim Larrañaga, told The Courier Journal he recovered with enough time to have a scout-team role during their run to the Final Four.

They fill some of Payne's experience void while also offering room for growth.

"I want to be a coach of development," he said. "I don't just want a quick fix.

"I'm glad they're here," he added, referring to the transfer additions, "but let's not be fooled that we're gonna take a kid who's older just because he's older and has more experience, which is important — but also, there's another side of it: I'm great at wanting to develop young people; and I think that's important."

One of his ACC colleagues, N.C. State's Kevin Keatts, offered a similar take.

"Fit — it's everything," said Keatts, a former U of L assistant under Rick Pitino whose Wolfpack is tied for fourth in the league when going by Torvik's experience metric.

"You would certainly love experience, and you love guys who can win, but you've got to plug those (roster holes) with (guys who) fit."

Two very early looks at Payne's overhauled roster — the Red and White intrasquad scrimmage and a 41-point exhibition win against Simmons College — indicate his four freshmen are long-term fits.

Dennis Evans, a 7-1 center, is a shot-blocking machine with a ways to go physically and technically. Kaleb Glenn and Curtis Williams are versatile wings who should only get better with more time on the court. Ty-Laur Johnson's pace and court vision make him a serviceable backup point guard to Clark already.

Against Simmons, they combined for 40 points on 14-for-20 shooting but committed 10 of the Cards' 22 turnovers. They tallied five assists.

"I'm challenging my freshmen to not be freshmen, to approach it with a different mindset — learn fast, grow fast, to have a maturity about it — so that we can have a chance to win games," Payne said Wednesday. "It's very hard to win if your young guys are being freshmen."

Only time will tell if they're up to the challenge, but Traynor and James have already seen enough to say they'll make a greater impact than last season's freshmen-turned-transfers, Fabio Basili (Texas Arlington), Kamari Lands (Arizona State) and Devin Ree (Louisiana Tech).

"These are some smart players, talented players," Traynor said. "With me and Mike as leaders, I feel like we're vocal enough to really help those guys get through it."

Added James: "They really have a good feel for the game. They don't play like freshmen. They come in, work hard every day, get in extra work; and their IQ is just different, for real. It's better than mine when I came in.

"Seeing that just gives you a lot of hope."

Check out Torvik's ranking of the ACC in terms of projected effective experience below. Each team's projected win total is in parentheses:

1. Clemson (20-10): 2.69

2. Georgia Tech (16-13): 2.32

3. Virginia Tech (20-9): 2.31

T4. North Carolina (21-8): 2.30

T4. N.C. State (18-12): 2.30

6. Florida State (14-16): 2.27

7. Pittsburgh (17-13): 2.16

8. Miami (20-10): 2.00

9. Wake Forest (16-13): 1.96

10. Boston College (16-14): 1.90

11. Virginia (18-12): 1.79

12. Louisville (12-18): 1.32

13. Duke (24-7): 1.24

14. Syracuse (13-16): 1.17

15. Notre Dame (10-20): 0.77

Reach Louisville men's basketball reporter Brooks Holton at bholton@gannett.com and follow him on X at @brooksHolton.

This article originally appeared on Louisville Courier Journal: Louisville basketball is hoping age won't define maturity in 2023-24