Parts Per Hundred or Parts Per One?

November 20, 2007 3:12 PM

What is the TERM for the three-decimal place, fraction-of-one "percentage" format used in baseball statistics?

Baseball "percentages" such as batting average, OPS, and even winning percentage are never expressed in regular percentages like 95% or 30%. Baseball people will refer to "percentages" of .950 ("nine-fifty") or .300 for those numbers.

Heck, OBP is "on base percentage", but also expressed as something like .449... and a hundred percent is written 1.000 but called "one thousand."

This seems to me to be a mangling of what "percent" means, which I think means parts per hundred, not parts per one.

Is there a concise but mathematically accurate term for this kind of expression? Calling it a "three decimal place, baseball-style percentage" or "a fraction of one to three decimals of accuracy, with padded zeros added when necessary" is quite the choice of mouthful.

Yes, I realize this is a heck of a waste of a MeFi question, but it's infected my brain now and Google's been little help.

posted by rokusan to sports, hobbies, & recreation (15 comments total)

My lazy butt wants to say "significant to three decimal places," but I've never heard that used in reference to baseball stats, sporting win/loss ratios, etc. I haven't a permilliage? of a clue.
posted by not_on_display at 3:21 PM on November 20, 2007

Per mil is the percent equivalent for writing parts-per-thousand. It even has its own symbol - ‰

This is not quite what the baseball stats are using, but it is related.

FWIW, I'm pretty comfortable with expressing percentages as decimals. 0.028 = 2.8% = 28‰. Most scientists I know seem to use the two interchangably.
posted by pombe at 3:27 PM on November 20, 2007

I don't have a huge problem with what you're saying as I see it as basically correct but I do have a problem when I see "9.1" to mean 9 and 1/3 innings or "9.2" to mean 9 and 2/3 innings.
posted by proj at 3:30 PM on November 20, 2007

Slugging "percentage" is a much worse mangling. It's a percentage that maxes out at 4.0!
posted by smackfu at 4:11 PM on November 20, 2007

Pomble, are you suggesting "decimal percentage?"

Smackfu, good point. Better example than OBP.

Still no good solution, though. At least I feel less stupid.
posted by rokusan at 4:38 PM on November 20, 2007

I'm a former sportswriter and sports agate editor. Unfortunately, I've never heard of a specific term for what you're describing here.

Realize that baseball stats were originally developed by a writer named Henry Chadwick in the late 19th century, and then filtered through early 20th century sportswriting and radio broadcasts, both of which had their own usages of jargon (e.g. "Three-fifty" is easier to say on the radio than "point three five," and "he's batting a thousand" is both more fun to write and say than "his batting average is 100 percent.").

Baseball is steeped in both tradition and a traditional love for silly wordsmithing -- witness the numerous nicknames for a "home run," which is itself a nickname. All these little language quirks are they way they are because ... well ... because that's the way they are! ;-)
posted by Cool Papa Bell at 4:45 PM on November 20, 2007

"Decimal percentage" sounds weird to my ears. If I was being pedantic, I would want to call it a probability, which is what is really being measured. I.e. an OBP of 0.447 means that in the past you have gotten on base 447/1000 times.

For something like slugging, I would use the more generic term "statistic" or "metric", but that's my scientist side talking, not the baseball fan side!

and don't even get me started on the lack of statistical significance of some of these numbers - I always love when they say that some hitter has an avg of 0.250 against a pitcher, when he's only faced the pitcher four times. Technically correct, but meaningless.
posted by pombe at 4:49 PM on November 20, 2007

Why not simply accept that "percentage" is a technical term in baseball jargon that happens to be homonymous with the mathematical term "percentage?"
posted by oddman at 5:46 PM on November 20, 2007

thousandths?
posted by Large Marge at 6:48 PM on November 20, 2007

Oddman: because I need a label for numbers in each format, basically. "This is a percentage, this is... baseball-percentage-thing." Good point, though.

C.P.B.: Yes, I am not really complaining... I just need a term so that I can refer to both kinds of "percentage" non-ambiguously. The stuff about "a thousand" and OBP and such was me attempting to help possible answerers who didn't know baseball lingo. I'm hep.
posted by rokusan at 7:27 PM on November 20, 2007

This seems to me to be a mangling of what "percent" means, which I think means parts per hundred, not parts per one.

It's still a percent, it's just written as a decimal.

Is there a concise but mathematically accurate term for this kind of expression?

Percent expressed as a decimal to three places.
posted by 23skidoo at 12:14 AM on November 21, 2007

Jeez, guys. Eleven responses without an answer?

"Batting average"
posted by yclipse at 3:08 AM on November 21, 2007

If you are just looking for a way to talk about both kinds of values clearly and you are willing to drop the criterion that both terms be "mathematically accurate," then I might try something like "baseball-percentage" or "sports-percentage" (since the use of "four-hundred" to mean 0.4 occurs in other sports too, especially when discussing winning percentage). All that you would have to do is provide a definition in a footnote or parenthetical comment.

As I hinted above, I would happily drop the desire for mathematical accuracy since, it seems to me, the sports scores aren't really math units.
posted by oddman at 4:25 AM on November 21, 2007

Yeh, yclipse, AskMe's definitely sub-Mendoza on this one.

I think oddman's done the best job of helping me resign to the fact there may be no good answer, here.
posted by rokusan at 8:35 AM on November 21, 2007

It's not exclusive to baseball. Like oddman mentions, it's used in winning percentages, and the same 3-place decimals are used in stuff like goalies' save percentage in hockey. In basketball, they actually do use percentages in the true sense of the word ("80.0% free throws," "22.5% three-pointers).

If anything, I guess baseball's "percentages" are just a misnomer. To add to the confusion, there are some stats that actually are percentages, like stolen base and stolen base rates. OBP and slugging are relatively recent stats, so I'm guessing they utilize the "percentage" moniker just out of familiarity.

The one stat that bugs me is the hits/at-bats ratio, which often uses a hyphen (he's 1-3 today). Whereas a pitcher's win-loss record, for example, will also use a hyphen (he's 1-3 for the year). I think Fox uses a slash for h/ab, which oughta be the right way, I say.
posted by TheSecretDecoderRing at 12:18 PM on November 21, 2007