Bill Walsh modernized the way many teams view the draft.

He changed the way people grade draft prospects, how they’re discussed, and put a premium on scouting the mental capabilities of players as well as their physical attributes. But one of his theories — the need to draft quarterbacks nearly every year — remains up for debate.

What the former San Francisco 49ers coach understood before most other teams is how valuable quarterbacks truly are. The truly great ones are rare commodities, and the position is difficult to draft and develop. He knew the position couldn’t be viewed and graded the same as others.

Unlike running back, wide receiver, or linebacker, a weakness at quarterback cannot be hidden or schemed around. You either have the right guy for your system or you don’t. Realizing this, Walsh selected a quarterback during his first four seasons at the helm — including three more after nabbing Joe Montana in the third round of the 1979 draft.

While it might be overkill to constantly be looking for quarterbacks — Walsh continued to draft quarterbacks nearly every other year even after Montana began emerging as one of the greatest of all time — there’s merit to the strategy.

You never know when something might happen to change your circumstances. Things happen. Players get injured or sometimes suddenly begin to fade. Walsh never wanted to be trapped in a perilous situation with no escape.

What Walsh understood, and what many teams fail to see today, is that it is better to have the next guy before you need the next guy. Teams like the New York Jets, Tampa Bay Buccaneers, Buffalo Bills, and many others have had to learn this lesson the hard way.

In other words, it’s better to be early than to be late. Extra quarterbacks can always be flipped for new assets if they’re any good and you no longer need them. And if you fail to locate those assets, at least the player revealed himself as a bust before he was needed.

This theory is pertinent to New Orleans this offseason because there has been talk about the Saints kicking around a succession plan for Drew Brees, which could mean the team will draft a quarterback in one of the next few drafts.

All of this was stated in a November report, which coach Sean Payton laughed off and which caused Brees to voice his ire during a radio interview.

“I know it has absolutely no validity to it,” he told Fox Sports Radio. “A lot of times you can look at who’s writing stuff and you can say, ‘All right, this guy is trying to make a splash or trying to make a name for himself.’”

But there likely is some validity to it, even if there is not an immediate need to replace Brees. Though he recently turned 36 and is coming off a season in which some of his decision-making was suspect, he proved he’s still more than capable by completing 69.2 percent of his passes for 4,952 yards with 33 touchdowns and 17 interceptions.

He can still win in this league and is among the best at his position. But there will come a time when he begins to fade, and the Saints can either begin to prepare for that situation now or wait and have to scramble once it’s too late.

The question is whether that time is now or a few drafts from now. After finishing last season 7-9, the Saints have glaring needs at a handful of positions and could use upgrades at several other spots. Selecting a quarterback, which is not an immediate need, could prohibit the team from addressing a current concern.

But whether it’s this year or down the road, the time will come for New Orleans to dive into the pool of quarterbacks if it is at all concerned about the long-term health of the franchise.

It’s what successful franchises do.

Circling back to the 49ers, when Montana’s tenure came to an end, Walsh already had Steve Young waiting in the wings to take over. Steve Mariucci was at the helm when Young stepped away from the game in 1999, and had selected Jim Druckenmiller in the first round of the 1997 draft to groom as the successor. But the 49ers traded him away before the 1999 season for conditional picks.

San Francisco then turned to Jeff Garcia, who was signed out of the CFL before the season, to take over when Young suffered his final concussion. San Francisco went 10-22 over the next two seasons before going 22-10 over the following two. It took nine seasons before the 49ers posted another winning record.

Around the same time, the Miami Dolphins were moving on from Dan Marino and turned to Jay Fiedler. The quarterback managed to post three seasons of 10 or more wins and helped Miami earn an AFC East title, but he was helped by a stout defense. During his time as the starter, he threw 66 touchdowns against 63 interceptions and completed 58.4 percent of his passes.

Miami has been in search of its next quarterback since Fiedler’s run ended in 2003, turning to the likes of Jay Feeley, Gus Frerotte, Joey Harrington, Celo Lemon, Chad Pennington, Chad Henne, and Matt Moore. After a rough run, it might now have answer in Ryan Tannehill.

It wasn’t that Miami didn’t try to locate a quarterback during that run. It spent several high draft picks on players like Henne, Harrington, Pat White, and Tannehill. What the Dolphins learned is that it is extremely difficult to find the right quarterback — especially when there is pressure to do so.

The Broncos tried to prepare for life without John Elway, but struggled in 1999 when Brian Griese, a third-round pick in the 1998 draft, led them to a 6-10 record. He rebounded the next year, leading Denver to the playoffs, but went 17-16 the next two seasons. It wasn’t until Jake Plummer took over in 2003 that Denver began finding consistent success.

Outside of the Montana-Young transition, one of the few other teams in recent history that has gotten it right without hiccups is the Green Bay Packers, who went from Brett Favre to Aaron Rodgers. Few other teams have taken their succession plan as seriously, but the results speak for themselves.

The New England Patriots are hoping they’ll be the next example after selecting Jimmy Garropolo in the second-round of last year’s draft. And when the time comes, the Broncos are hoping Brock Osweiler can fill in once Peyton Manning steps away.

Considering how few players are even capable of starting at quarterback in the NFL, let alone how many play the position well, the odds of landing two premiere players in succession is slim — even if the Indianapolis Colts made it look easy to forget the lost year between Peyton Manning and Andrew Luck.

But the odds of finding that next player are zero when you don’t even try to find him. It’s almost always better to start the search early than late. Otherwise, you might end up talking about how you should have prepared instead of being applauded for how you did.