The San Francisco 49ers are still undefeated with Brock Purdy under center since he took over the starting quarterback position in the middle of last season, and a lot of fans have downplayed his performance due to the strength of the 49ers' roster, which has caused 49ers head coach Kyle Shanahan to come out with a passionate defense of his quarterback.

“That's pretty ridiculous,” Kyle Shanahan said, via David Bonilla of 49ers Webzone. “You just got to watch the tape. I mean, he plays at a high level every time he's been out there. And he's done it in a lot of different situations versus a lot of different defenses, on the road, at home, in playoff games, when injured.”

When fans call someone a ‘system quarterback' it is usually seen as a dig. It has been thrown at many quarterbacks over the years, even Tom Brady has received that criticism.

“You can't do all that stuff [if you're a system quarterback],” Shanahan said, via Bonilla. “He's been out there too long. It's on tape.”

Shanahan does have a point. Sometimes when quarterbacks play well in their first few games or so, teams adjust after getting some tape on him and limit what that player does well.

It will be interesting to see how long this winning streak goes. This Sunday is a big game coming up against the Dallas Cowboys at home. The Cowboys are one of the contenders in the NFC, so it will be telling about where both teams stack up.