From a defensive standpoint, Ryan has the knowledge and flexibility general manager A.J. Smith is looking for. He has it all in terms of pedigree as the son of football legend Buddy Ryan, plus the requisite Super Bowl ring.
Known as a players' coach, Ryan also has an easygoing personality, a must to work with Smith, a demanding taskmaster who delights in letting everyone know he's the boss and that the buck stops with him.
It's looking more and more like a two-horse race since USC coach Pete Carroll removed himself from consideration between Ryan and San Francisco 49ers offensive coordinator Norv Turner, a genial retread who would make sense given that quarterback Philip Rivers' development would seem to be paramount for a team with major Super Bowl aspirations, a proven defense that could practically run on auto pilot and a future Hall of Fame running back in LaDainian Tomlinson.
Smith knows that he can't have this move fail, or he's out.
Salary and control are two important elements in this race. Turner is reportedly amenable to hiring former Buffalo Bills defensive coordinator Ted Cottrell as his defensive guru.
Ryan is inclined toward former Ravens secondary coach Donnie Henderson, who was recently fired by the Detroit Lions as their coordinator after a previous stint with the New York Jets.
That shouldn't be a deal-breaker, but who knows?
Here's the interview lineup so far: 49ers assistant head coach Mike Singletary, Ryan, Chicago Bears defensive coordinator Ron Rivera, who also made a strong impression, Atlanta Falcons defensive coordinator Mike Zimmer and New Orleans Saints defensive coordinator Gary Gibbs.
"These men all have winning backgrounds," Chargers president Dean Spanos said. "They've been part of successful programs and have attributes that we think could positively contribute to what we're trying to accomplish here."
At this point, Ryan has done all he can to secure the job.
Look for a decision at some point this week and don't be surprised if Ryan becomes the second NFL head coach in his football-loving family.
Aaron Wilson covers the Baltimore Ravens for the Carroll County Times in Westminster, Maryland.