In August, Geno Smith was trying to hold off Drew Lock for the Seattle Seahawks' starting job. Nobody believed he'd be any good even if he won that competition.

At least Smith was on the radar of NFL fans, though mostly for his failed stint with the New York Jets. Nobody knew Brock Purdy unless you're a Big 12 fan, study preseason football or are really into Mr. Irrelevant history. Purdy was fighting with Nate Sudfeld for a San Francisco 49ers' roster spot, and won that job based on a good preseason. Nobody expected him to be a factor this season, or maybe ever in the NFL.

If someone said then that Thursday night football in week 15 would feature Purdy starting against Smith, everyone would have made really early plans to go holiday shopping that night. But it's actually a really fun and compelling matchup between two of the best individual stories of this NFL season.

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Smith has been very good all season, helping the Seahawks into playoff contention. Purdy got his shot a couple weeks ago when the 49ers, already down Trey Lance, also lost Jimmy Garoppolo to injury. Purdy has played very well in two wins.

Quarterbacks coming out of nowhere to become key players isn't unheard of, but it's rare. We'll see two fantastic success stories on Thursday night.

Geno Smith emerged at age 32

Smith and Purdy came to their success from different paths.

Smith was a second-round pick and had some good moments with the Jets, but his time there might be best known for him having his jaw broken on a punch from then-Jets defensive end IK Enemkpali. After two seasons Smith was quickly onto the backup phase of his career. After the Jets he spent time with the New York Giants (famously starting once when Ben McAdoo benched Eli Manning to end Manning's games played streak), Los Angeles Chargers and then the Seahawks. He started five games in the six seasons before this one.

Smith got off to a hot start against the Denver Broncos in Week 1, and has kept it going all season. He has 3,433 yards, 25 touchdowns, eight interceptions and a league-best 71.5 completion percentage. Breakout seasons don't usually happen at age 32 after six years on the benches of four different teams, which makes Smith's 2022 season remarkable.

Purdy's ascension to the starting job followed a more familiar path. He was a third-string rookie and the 49ers had no other choice when they lost their first two quarterbacks. Purdy had a good college career at Iowa State, but isn't physically impressive. That's why he lasted until the final pick of the draft, playfully nicknamed "Mr. Irrelevant."

What's also familiar about third-stringers being forced into action is they usually look overmatched. Purdy hasn't at all. He had thrown only nine NFL passes before being pressed into duty two weeks ago, and one was an interception. Plenty of 49ers fans didn't have any expectations for Purdy when he entered the game against the Miami Dolphins, because they probably didn't know who Purdy was.

Then a funny thing happened: Purdy has played well enough that the 49ers' Super Bowl dreams are still alive.

Brock Purdy has been a revelation

Purdy threw for 210 yards and two touchdowns off the bench in a 33-17 win over the Miami Dolphins. On Sunday he had 185 yards and two passing touchdowns, with a short rushing touchdown too. The 49ers beat the Tampa Bay Buccaneers 35-7. Purdy doesn't look nervous or out of place. The 49ers seem energized by him.

“He’s going to keep slinging it and ripping what he sees, and I think our guys feel that,” 49ers coach Kyle Shanahan said, according to NBC Sports Bay Area. “When you’re like that, it gives a lot of people confidence because you know it’s just a matter of time.”

We've seen quarterbacks come from nowhere to become NFL superstars. Tom Brady is the most famous example. Tony Romo and Kurt Warner are two others. Rich Gannon is a rare example of a QB who emerged in his 30s to become a star, and he's probably the best comparison to Smith. Gannon won an MVP and made a Super Bowl. Mark Rypien was a sixth-round pick who won a Super Bowl MVP award with Washington during the 1991 season. Purdy is trying to follow that path. Though to be fair, there's no perfect comparison to Purdy. No rookie quarterback has ever started a Super Bowl, much less the final pick of the draft who started the season on the third team.

Those type of underdog stories, especially at the most famous position in sports, are worth celebrating. Purdy vs. Smith wouldn't have sounded very appealing a few months ago. It's pretty cool now.