Matthew Stafford has described himself as his "own worst critic" ahead of the first week of the NFL season.
The Detroit Lions quarterback, who was the number one draft pick in 2009, struggled to find the end zone last season, completing less than half the number of touchdown passes that he made in 2011.
The 25-year-old told the team's website: "It is what it is. We get a ton of credit when we win and a ton of blame when we lose. [Reality is] probably somewhere in between. This is a team sport, but at the same time, in this league especially, if your quarterback plays well, you have a chance to win the game. I'm no stranger to that
"I'm my own worst critic, except for some of those guys are pretty bad. Don't get me wrong, I take a close look at my game at all times and make sure I'm playing my best.
"I've been through a lot, I've been through obviously a 10-6 season and I've been through a 4-12 season. I've seen just how close that difference is as far as what a quarterback can do to help his team win or lose. I'm determined to be on the winning end of it."
The Lions play the Minnesota Vikings on Sunday.