There's no agreed-upon definition for what the declining back end of a quarterback's career is supposed to look like. If there was, there probably would be a few telltale markers. More interceptions than touchdowns. Fewer wins and no recent playoff appearances. More hits in the pocket and less ability to move around the field. Sketchy decisions, which used to be covered up by big plays, exposed for big mistakes.
In other words, it would look a lot like Eli Manning's last two-plus seasons.
Which is why whispers are starting to circulate that the Giants quarterback is on the downslope, that at age 33 his best days may be behind him.
With each ineffective game and each muddling loss, Manning seems to be slipping closer and closer to the end. At an age when some passers in the NFL are finding their prime, there are some who believe Manning is beyond his.
Manning, though, remains confident that as the team enters its 90th season with its home opener against the Cardinals on Sunday, he still is the player he once was and can bring the Giants another championship before his career is over.
"No doubts," he said. "I feel confident we can play at a high level and this offense can score points and we can make plays and I can be a good leader and a good player. I'm going to keep working. I'm going to be 100 percent committed to go out there and try to put this team in a situation to win."
And in the face of those who don't think Manning is a good fit for the West Coast offense the team is installing, coordinator Ben McAdoo gave the quarterback a strong vote of confidence this week.
"He is a perfect fit for this offense," McAdoo said.
One of the improvements McAdoo noted in the loss to the Lions last week was in Manning's footwork and his improvement in the fundamentals of the offense.
"He's seeing things," Mc-Adoo said. "He is not 100 percent, but who is? At the same point in time, he is making progress and I have 100 percent confidence in Eli Manning."
"Obviously as the quarterback of this team, any team, you are going to get the brunt of the blame," said wide receiver Victor Cruz, who heaped a little perceived criticism on Manning this past week by suggesting that he and Rueben Randle need more passes thrown their way. "It's not all his fault. It's not all everything he is doing. It's all of us collectively understanding what we have to do, executing the game plan and moving on from there. Obviously, being the quarterback, you get the majority of the blame, which is unfortunate."
Manning knows that and has spent the majority of his career with the Giants deflecting it well. His most useful shield has been the occasional Super Bowl trophy, which seems to quiet the critics for a little while. But the Giants are 16-17 since they last held the Lombardi Trophy. Manning was 13-12 in his first 25 NFL starts. He is 10-15 in his last 25, dating to the middle of the 2012 campaign.
"We are going to have to grind through some times," Manning said. "It's not all going to be perfect and easy. I think each game you are going to get better. Each game things are going to come up that you are going to learn from. You might not always be ahead of the game on some things. That's part of it, but still you can go out there and be efficient. You can make improvements, make some big plays, do things."
He has to start doing things soon. Or more people will believe he never will again.