NFL quarterbacks and coaches are all about the X’s and O’s.
But when it comes to the multiplication and division that goes into determining a quarterback rating, they typically look the other way.
“I can’t even explain it to you, so it gives you an idea of what I think about it,” Broncos coach Mike Shanahan said.
Still, passer rating has been popularized by fans and agents as the best tool to judge a quarterback’s efficiency. Problem is, the formula is 35 years old and has not been adapted to the times.
Devised in 1973 by Don Smith, a retired Pro Football Hall of Fame vice president, the system is a mathematical formula based on a quarterback’s completion percentage, passing yardage, touchdowns and interceptions.
It does not include win-loss ratio.
The best possible rating is 158.3, and the worst zero. Smith originally projected an average score of 66 2/3, but today’s average is significantly higher.
From 2000 to 2003, the average rating was 78.9. In 2004 it jumped to 82.8, and it was 83.5 last season.
Broncos backup quarterback Patrick Ramsey doesn’t know what his career rating is, and quite frankly, he doesn’t care.
“It’s not important to me,” Ramsey said. “You want to complete passes, score touchdowns and keep the ball away from the defense. Other than that, I don’t look at anything. I have no idea what my rating has ever been in any game.”
If guys like Ramsey don’t care, why should fans?
“Maybe it has something to do with fantasy (leagues), or something they look at overall judgment of effectiveness,” Ramsey said. “In my mind, it’s all about scoring points and keeping the ball away from the defense.”
Shanahan said agents often bring up the rating during contract negotiations — when the rating works in their favor.
“If a quarterback is having a good year, usually the ratings are fairly consistent, because a lot of factors are involved,” Shanahan said. “But the big one is winning, and of course that’s more important than any rating.”
Legendary Broncos quarterback John Elway ranks 46th among all quarterbacks with at least 1,500 passing attempts. Elway’s career rating is 79.86, or below average in today’s game. Yet Elway is the only QB to start in five Super Bowls, winning two.
Elway’s successor, Brian Griese, has the 17th best all-time rating of 84.54.
Steve Young has an all-time high rating of 96.81, but he is just one of two Hall of Famers in the top 10 in that department — although Peyton Manning (No. 2, 94.37) and Tom Brady (No. 8, 88.36) undoubtedly will join him in Canton, Ohio.
Mike Chambers: 303-954-1357 or mchambers@denverpost.com
Can you do the math?
Here is the formula for calculating quarterback rating:
a = (((Comp/Att) * 100) -30) / 20
Completions divided by attempts, multiplied by 100. Subtract 30, divide by 20.
b = ((TDs/Att) * 100) / 5
Touchdown passes divided by pass attempts, multiplied by 100, then divide by 5.
c = (9.5 – ((Int/Att) * 100)) / 4
Start with 9.5, and subtract INTs divided by att., multiplied by 100. Divide by 4.
d = ((Yards/Att) – 3) / 4
Passing yards divided by pass attempts. Subtract 3, then divide by 4.
a, b, c and d
The sum of each step cannot be greater than 2.375 or less than zero.
QB Rating = (a + b + c + d) / .06
Add the sums of steps 1 through 4, divide by .06
* Rating calculator: Take the easy way out at
