Every time a 49ers quarterback does well, Kyle Shanahan gets most of the credit. And he deserves it, some of the time.NFL coaches and executives recently were asked to rank the top 10 quarterbacks in the NFL, and Purdy didn't make the list, presumably because the voters think he's a system quarterback who owes his career to Shanahan, which may or may not be true.Shanahan deserved the credit when Jimmy Garoppolo was the 49ers' starting quarterback. He produced like a top-10 quarterback in the NFL with Shanahan calling plays. Then Garoppolo signed with the Raiders, crashed and burned, and accepted his status as a backup with the Rams. Now, he's a free agent.Shanahan also deserves the credit when it comes to Mac Jones, who was a failure as a starting quarterback on the Patriots and the Jaguars. We've seen what he looks like in a bad system. He needs a good play caller like Shanahan. In eight starts last season, Jones ranked 10th in the NFL in QBR. Like Garoppolo, Jones thrived in Shanahan's system.Which brings us to Brock Purdy. Purdy played well in college, but was unremarkable, which is a big reason he went to Iowa State and was the last pick in the Draft. Then he joined the 49ers, learned Shanahan's system, and now he's the highest-rated quarterback of all time. Surely, Purdy is another product of Shanahan, right?To a degree, yes. If Purdy had been drafted by the New York Jets, he might not be a starter right now. And when Purdy first took over as the 49ers' quarterback, Shanahan set him up for success.To begin with, the running game was elite. Christian McCaffrey was in his prime, and defenses had to load the box to slow him down, which opened up the play-action passing game. And the receivers were elite. Brandon Aiyuk and George Kittle were in their primes, and Deebo Samuel was just past his. They could beat defenses deep, and they could beat them after the catch.Purdy's job was easy. And yet, it was clear that he was a playmaker, too. Not just another Garoppolo. Purdy can do special things outside the structure of Shanahan's system. He's one of the most elusive quarterbacks in the pocket, and he throws with incredible touch. Those skills would translate to any system.And for the past two years, Purdy's job hasn't been easy. Suddenly, certain defensive coordinators seem to have Shanahan's number. Suddenly, the 49ers run game is among the worst in the NFL. Last season, it ranked 30th out of 32 teams in yards per carry. That has nothing to do with Purdy. That's Shanahan's department.Shanahan is the one who refused to trade Aiyuk and then fractured the relationship with him before voiding his guarantees and replacing him with Mike Evans, who's old. Shanahan is the one who extended McCaffrey and continues to use him like he's still in his prime, even though he's old and has no juice left. Shanahan is the one who extended George Kittle in his 30s, and now he's old and coming off a torn Achilles.In 2026, here's what Shanahan provides Purdy: a weak offensive line, a bad run game, a bad play-action-passing game, minimal yards after the catch, and an old supporting cast.As a result, Purdy has to carry the offense. Purdy was the 49ers' leading rusher in their playoff loss to the Seahawks. Purdy has to hold the ball forever to hunt big plays. This leads to turnovers and injuries.All of Shanahan's quarterbacks throw tons of picks and get injured. Garoppolo had the same fate. It's time to acknowledge the common denominator, and that's Shanahan.He needs to do a better job as an offensive coordinator this year. He's coasting on reputation.Add us as a preferred source on GoogleFollow