Ask Farmer: How were football’s scoring system and passer rating determined?

Have a question about the NFL? Ask Times NFL writer Sam Farmer, and he will answer as many as he can online and in the Sunday editions of the newspaper throughout the season. Email questions to: sam.farmer@latimes.com

Scoring in football has always baffled me. How do they determine a touchdown is worth 6 points? Field goal 3? Safety 2? Then the extra point — why? The most meaningless play and point in football, and how did it originate?

Bob Nydam, Sierra Madre

Farmer: The scoring system does seem arbitrary, and the only significant change to it came in 1994 when the league adopted the two-point conversion. I reached out to Jon Kendle, archivist at the Pro Football Hall of Fame, to see whether the system was always the way it is now, or whether there was an evolution on the valuation of different scoring plays.

This doesn’t address why the points values are what they are, only that the system was fluid in the early years of the game.

Turns out, having a good kicker was hugely important in the early days of football. The scoring values in 1892 were five points for a field goal, four points for a touchdown, and two points each for a PAT (point after try) and safety. Five years later, touchdowns were increased to five points, and a PAT was reduced to one.

The tinkering continued. In 1904, the field goal was reduced to four points, and then to three five years later. In 1912, the touchdown was bumped up to the current value of six points.

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Why does the NFL’s passer rating max out at 158.3? Why should a guy who goes 10 for 10 for 800 yards and 10 touchdowns have the same rating as a guy who goes 20 for 25 for 358 yards and three touchdowns?

Darren Pollock, Pasadena

Farmer: For this, I turned to Steve Hirdt, executive vice president of the Elias Sports Bureau, a premier resource for sports statistics.

Hirdt said that the passer-rating system was originally intended to evaluate a large body of work, such as how a quarterback performed over the course of his career or during a season, as opposed to a game-by-game (or sometimes quarter-by-quarter) assessment. Therefore, nobody is going to hit the ceiling with the highest possible rating.

“If you have a first half where you’re 10 of 12 for three touchdowns and no interceptions for 200 yards,” Hirdt said, “you don’t need a passer rating to amalgamate those numbers and know that the guy’s had a strong first half.”

Hirdt said the application of passer ratings to much smaller segments only reflects a wider trend in the stats business. People want to attach a tabular, computerized explanation for everything.