SANTA CLARA >> When is it not all about the 49ers’ QB1? When the quarterbacks are inside their meeting room.

Every year, it undergoes a metamorphosis, all in search of the right mix to produce an ideal starter, on any given Sunday, any given season.

A healthy Brock Purdy is that quarterback, in coach Kyle Shanahan’s ideal scenario for 2023.

As last season’s four-quarterback relay showed, you better have a great committee of quarterbacks and coaches. Call it a team’s subcommittee, or committee of subs, if you will.

Quarterbacks come and go (see: 15 overall since 2017). Expectations remain the same: lead the 49ers to their first Super Bowl win since Steve Young last did so in the 1994 season.

ROOM WITH A VIEW >> This year’s dynamic offers a radically different QB room.

Returners: Purdy and Trey Lance, along with position coach Brian Griese and his assistant, Klay Kubiak, Klint’s younger brother.

Newcomers: Veteran quarterbacks Sam Darnold and Brandon Allen, along with assistant Klint Kubiak as the passing-game specialist.

Departures: Two-time NFC Championship Game starter Jimmy Garoppolo, journeyman backup Josh Johnson, and former passing-game coordinator Bobby Slowik.

Presiding over that room is their seventh-year coach, Shanahan.

“I don’t want to compare it to other years,” Shanahan said after Tuesday’s practice, “but we have two guys who are talented enough to be taken in the top five of the draft, and we have another guy who played like it last year.”

Translated: Great expectations were immediately bestowed upon No. 3 overall draft picks Darnold (2018, New York Jets) and Lance (2021, 49ers), while Purdy performed like a top-level quarterback only seven months after being taken with the 262nd and final pick in last year’s draft.

“I like the three guys we got,” Shanahan added, “and I’ve always been a fan of Brandon Allen. Just watching him throughout his career and to be able to get him in here also, I feel really fortunate with our four.”

Call them The Fortunate Four. Ultimately, that foursome will be whittled down, much of that depending on how and when Purdy returns from the March 10 surgery on his throwing elbow.

NOT A TRUE QB COMPETITION >> If Purdy’s recovery stays on track, that could make any quarterback competition relatively moot if he’s available for the Sept. 10 opener at Pittsburgh.

Contingency plans are in place. Lance opened OTAs taking all the first-team reps, while Darnold gets his feet wet with his third team in four years. Allen is only getting a couple of snaps in team drills, which was enough for Purdy last summer to show his potential, mind you.

It is not a bitter battle. Lance and Darnold high-fived each other as they rotated spots during Tuesday’s practice, and all quarterbacks speak highly of their growing chemistry and communication.

In Tuesday’s 7-on-7 drills, Purdy was an observer while Lance, Darnold and Allen carried out their jobs in mundane fashion. Nothing was revolutionary. Nothing was cringeworthy, either.

I GOT YOUR (QUARTER)BACK >> Afterward, the top three QBs were asked about that revamped quarterback room, which saw Garoppolo come and go with injuries since 2017 before his free agency departure this spring for the Raiders.

Purdy said the “dynamic is great,” attributing that to the diverse background of each quarterback, such as Allen backing up Joe Burrow in Cincinnati, Darnold previously working at Carolina under long-time NFL quarterback Josh McCown, and Lance providing familiarity.

“We all get along really well and I’m really excited moving forward with this group of guys,” Purdy said.

Added Darnold: “It’s just really cool the conversations that we get to have in the quarterback room, especially like you mentioned with Coach Griese in there, just being able to talk about the position and talk about how to kind of deal with those things and deal with adversity and even deal with success at times.”

Darnold’s arrival did not cast Lance onto the offseason trade market, as some suspected it might.

QB HISTORY SINCE 2017 >> This is where a lot of quarterbacks have been. A year-by-year account of who’s had entry into the 49ers’ QB club:

2017: Brian Hoyer, Matt Barkley, C.J. Beathard, Nick Mullens, Garoppolo

2018: Garoppolo, Beathard, Mullens, Jack Heneghan, Tom Savage

2019: Garoppolo, Beathard, Mullens, Wilton Speight

2020: Gaeoppolo, Beathard, Mullens, Broc Rutter, Josh Johnson, Josh Rosen

2021: Garoppolo, Lance, Rosen, Johnson, Nate Sudfeld, Tyler Bray

2022: Garoppolo, Lance, Purdy, Sudfeld, Kurt Benkert, Jacob Eason, Johnson