What is the origin of the 20-80 scale used in baseball scouting?
June 30, 2011 8:54 PM   Subscribe

What is the origin of the 20-80 scale used in baseball scouting?

Scouts for major league teams rank prospects in several areas (power, speed, etc.) on a 20-80 scale. Some use a 2-8 scale which is pretty much the same thing. I can't find anywhere on the Internet where anyone has a reason for this scale, rather than a 0-60 scale or 0-100. It reminds me of the 200-800 scoring system used in standardized tests issued by the Educational Testing Service. And nobody seems to have an answer for why ETS uses that scale, either.
posted by sitecoach to Sports, Hobbies, & Recreation (4 answers total) 1 user marked this as a favorite
This quote is from the world of hockey scouting, but the reasoning sounds like it would apply to all sports:
You may read this and wonder why the scale goes from 20 to 80 and not from 0 to 100. Well, simply put, it's because of standard deviation. To those mathematically deprived, it means that according to a normal distribution of talent 2/3rds of the players should fall between 40 and 60, with the overwhelming majority falling between 30 and 70. It's a proven way to make sure the average players and varying notches are spread out well enough but not too much. While the theory stems from standard deviation, not all the tools have a perfectly normal distribution. Many more players have an 80 physical game, and very few have an 80 skating or an 80 shot.
posted by Rhaomi at 9:33 PM on June 30, 2011

That seems to be saying that scouting scores have mean 50
and standard deviation 10. SAT scores are supposed to have mean 500 and standard deviation 100, and always end in 0. It wouldn't surprise me if the sports scouts
directly copied the SAT.
posted by madcaptenor at 9:39 PM on June 30, 2011

If you're on Twitter, @keithlaw might be a good bet to answer this for you.
posted by auto-correct at 12:46 AM on July 1, 2011 [1 favorite]

What everyone else said. Probably the thought process went "let's make the mean 50, that's a nice round number"... and then the statisticians said, "OK, then your standard deviation will be 16.6 repeating.... OR we could make the mean 50 and the standard deviation 10, which means we'll only have scores between 20 and 80." "Hmm, 16.6 is a pain in the rear, whereas 10 is round* and easy-to-remember..."

*In base 10.
posted by anaelith at 12:59 AM on July 1, 2011

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