A decade after Indianapolis made Manning the first player drafted in 1998, leaving Leaf for San Diego at No. 2, the Chargers have recovered. Their playoff victory over Manning's Colts in January proved as much.
But the most regrettable draft outcome in San Diego sports history continues to reverberate well beyond Southern California. Leaf's quick demise impacted the quarterback fortunes of four franchises, demonstrating how draft-day mistakes can carry unintended consequences.
If Leaf had performed to expectations, Michael Vick might never have found his way to Atlanta. Drew Brees never would have flourished in San Diego, perhaps diminishing his chances of landing a long-term deal in New Orleans. The New York Giants might have been unable to swing a draft-day trade with San Diego -- or anyone else -- for franchise quarterback Eli Manning. Philip Rivers certainly wouldn't be lining up under center in San Diego.
And Bobby Beathard, the Chargers' general manager during the 1990s, would be fielding fewer questions about Leaf and more about his role in building seven Super Bowl teams across four decades.
"I thought then and I think today, more sure than ever, that Bobby Beathard belongs in the Hall of Fame," Colts president Bill Polian said. "You never hear his name mentioned simply because of that one pick, and to me that is a tragedy. No one, including [former Giants general manager] George Young, has done what Bobby Beathard did in his career."
Few players have undone as much as Leaf managed to undo.
"The one big thing with Ryan, I think he had the ability," said Beathard, who is retired and living in California. "When he came to the first minicamp, even the veterans were saying, 'Man, this guy can throw.' But he self-destructed. It was all the other stuff that interfered with everything he did."
Jon Niednagel was right. The brain-typing consultant had warned the Chargers against drafting Leaf, claiming the quarterback's makeup was a poor fit for the position and a terrible match for then-coach Kevin Gilbride. Beathard said he listened, but he didn't know enough about Niednagel to heed the warning. And he figured no human could possibly clash with easygoing assistant June Jones, then the team's quarterbacks coach. Leaf proved otherwise.
"Guys can be jerks, but I've never seen a guy that worked harder at alienating his teammates," Beathard said. "Junior Seau, Rodney Harrison, they came to me and said, 'Bobby, this guy is killing me.'"
Leaf's final NFL numbers said it all: 21 starts in 25 games, with 14 touchdowns, 36 interceptions and 65 sacks.
The Chargers, back in the market for a quarterback before Leaf turned 25, considered drafting Vick first overall in 2001. Contract negotiations stalled, however, and the Leaf experience was still a powerful deterrent to taking a quarterback early. The Chargers sent the first pick to Atlanta for a package that included the fifth pick, used for running back LaDainian Tomlinson. The Chargers, led at the time by late GM John Butler, then took Brees in the second round.
Brees had yet to emerge as a long-term starter when San Diego used the first overall choice in 2004 for another quarterback. Butler's successor, A.J. Smith, drafted Eli Manning, then sent him to the Giants for the rights to Rivers, chosen fourth overall. San Diego had used the draft to land three franchise quarterbacks in seven years.
All because Leaf bombed. And because the Colts wouldn't give San Diego a shot at the quarterback the Chargers wanted most: Peyton Manning.
Beathard had contacted Polian to inquire about the top pick's availability. Told the choice wasn't for sale, the Chargers settled for the second overall pick, acquired from Arizona for the third and 32nd picks, plus a 1999 first-rounder and two players.
"Bill told me at that time that they weren't sure which quarterback they were going to take," Beathard said. "I never knew if that was true or not, but Bill I think was being kind to say that even to this day. I do know who we would have taken. We would have taken Peyton because of my familiarity with his parents and the family. But that didn't mean there was anything bad that way with Ryan at the time."
Predraft talk painted Leaf as the more dynamic athlete and Manning as the more polished product.
"Manning-Leaf was really split when you talked to people," said Colts coach Tony Dungy, who was with Tampa Bay at the time. "We weren't looking for a quarterback, but I remember that era, and it was really split."
Polian said he knew Manning would be the likely choice about three-quarters of the way through the evaluation process. But he made no public declarations.
"I'm not a big proponent of going to college workouts because so many are scripted by the agents," Polian said, "but we worked out both guys personally without a script.
"It was obvious -- very obvious -- after the workout that Peyton far and away had the stronger arm, threw a tighter ball. Everything you had heard, all the scuttle, was that Leaf was the far better athlete, Peyton was a product of the system, Peyton had a weak arm. Just the opposite was true when you watched the workout. It drove home the idea that you better go through the process."
"I loved Fred Taylor," Beathard said. "I really thought that guy was something. He was such an instinctive running back."
Taylor went ninth overall to Jacksonville, where he has 10,715 yards rushing and is coming off a Pro Bowl season at age 32. Woodson and Wistrom have also enjoyed long, productive careers. Wadsworth went to Arizona at No. 3, but knee injuries derailed his career almost before it began.
"Afterwards I thought, 'I wonder if that trade hadn't worked out and we took Wadsworth, maybe Wadsworth wouldn't have been hurt and maybe he would have been a good pass-rusher and that would have worked out,'" Beathard said.
Had San Diego held onto its 1999 first-round choice, which Arizona used for receiver David Boston at No. 8 overall, the Chargers probably would have drafted defensive tackle Anthony McFarland, who slipped to Tampa Bay at No. 15.
"McFarland was amazing," Beathard said. "He was a guy that could be taken way up probably higher than even the eighth pick and be a good pick, if he controlled his weight."
In the end, the Chargers simply couldn't pass up a shot at a franchise quarterback. And Beathard was well qualified to make the call.
The longtime personnel evaluator helped bring future Super Bowl MVP Mark Rypien to the Washington Redskins as a sixth-round choice in 1986.
Beathard made Stan Humphries a sixth-round choice two years later, eventually bringing him to San Diego, where Humphries led the Chargers to their lone Super Bowl appearance.
While Humphries was still developing in 1993, Beathard used the Chargers' eighth-round pick that year for Trent Green, another future NFL starter.
Coaches showed little interest in developing Green, who lasted only one season in San Diego. When Humphries' body broke down, leading to his retirement after the 1997 season, the Chargers suddenly needed a franchise quarterback.
"One scout in our organization said, 'Let's take another position early and then get Brian Griese, who is not that type of quarterback, but he's smart and we can better ourselves with him until a great one comes along,'" Beathard said. "We talked about it briefly, but we thought, 'No, if you can get a franchise guy, we have to do that.'"
Griese went to Denver in the third round in 1998.
In Leaf, the Chargers thought they were getting a player who would impact the NFL for 10 or 15 years -- as a player, not as the man whose failure impacted so many others. Leaf, 31, would be entering his 11th season if all had gone to plan. Instead, he is quietly serving as quarterbacks coach at West Texas A&M.
"It has come out nicely in that Ryan has gotten his life back on track and is in coaching and by all accounts doing well, and that is good, too," Polian said. "When you talk about judging the two guys, people want to say Leaf didn't have any talent. Of course not. He had the charisma and leadership. He was just immature. He was not ready to come into the league and handle the burden of leading the franchise to a Super Bowl championship."
Leaf wasn't the only draft bust of 1998. Here is a rundown of 1998's first round:
Mike Sando covers the NFL for ESPN.com.