12/21/24
August 12, 2015
All 15 MLB Home Teams Won Last Night -- Setting a Record: All 15 home teams won yesterday in Major League Baseball, the first time that's ever happened. If every game was a 50/50 proposition, the odds of this would be 1 in 32,768. The previous record for home victoriousness was when all 12 teams won on May 23, 1914. In other statistical milestone news, Alex Rodriguez is the last active Major Leaguer to make his debut before the 1994 strike.
Viewing every game as a 50-50 proposition independent of all others, STATS figured the odds of a home sweep on a night with a full 15-game major league schedule at 1 in 32,768 -- or about once every 80 years, according to Louis Mittel, a a doctoral candidate in statistics at Columbia University.
I like that they didn't get a professor, or an actual "doctor" of statistics, but a "doctoral candidate". Here is his page on the Columbia University website.
How does this guy get picked for the citation? I wonder if he's buddies with someone on the ESPN writing staff.
posted by grum@work at 12:05 PM on August 12, 2015
I'm bad at stats, but even I could puzzle that one out.
I can tell you that a LARGE percentage of the people who are reading ESPN (or any website) do not have even a basic statistical understanding of odds/statistics/probability.
They'll be the kind of people that mock someone for choosing 1-2-3-4-5-6 as their Powerball numbers because "what are the chances THOSE numbers will come up".
posted by grum@work at 12:11 PM on August 12, 2015
Goddammit, now I have to change the combination on my luggage. Thanks, grum.
posted by Etrigan at 12:16 PM on August 12, 2015
So..... (Mr Grum), as a baseball newcomer from Down Under:
Based on actual home field advantage, rather than a flat 50/50 chance, I presume the odds would be slightly better than 1 in 32,768. Also did the "once every 80 years" conclusion allow for the number of occasions each season where all 30 teams are in action on the same day?
Have you got data to calculate this, and conversely the odds of all away teams winning in the same circumstances?
posted by owlhouse at 10:20 PM on August 12, 2015
The home team has a slight advantage in baseball by batting last (plus the usual "home team advantage" in most sports).
Last year, the home team won 52.5% of the games.
So using that as the odds, it's more like 1 in 15,762.
I don't know where the "once every 80 years" comes from, or how it was calculated.
There haven't always been 30 teams (only for the last 17 years), and not everyone plays every day of the week (only guaranteed full schedule on Friday, Saturday, and Sundays).
The Sports Illustrated article about this has more info:
According to the Elias Sports Bureau, the official statistician for MLB, the previous record for most games on a single day in which every home team won was 12, set on May 23, 1914. Home teams have gone 11-0 six times, the last being on Sept. 16, 1989, according to STATS.
The last time all home teams went undefeated when there was more than one game on the schedule was Aug. 28, 2008 when the home teams went 8-0, according to STATS.
I can't find any record of the last "all-visitor-wins" day, but based on the home advantage % from above, the inverse (47.5% win percentage for the visitors) would mean a 15-visitor-win-day would happen about 1 in 70,729 times.
posted by grum@work at 10:38 PM on August 12, 2015
Thanks Grum.
Asking you is easier than clearing the cobwebs from the part of my brain where Stats B01 chose to die.
posted by owlhouse at 12:30 AM on August 13, 2015
This may just be a warm up for a more compelling statistical analysis, which would be:
How many days in a row will all Canadian MLB teams win their games, regardless of whether home or away?
posted by beaverboard at 09:49 AM on August 13, 2015
The hype train in Toronto is an unstoppable locomotion right now.
posted by grum@work at 11:48 AM on August 13, 2015
Some lunatic in Ireland won $100,810 on a 15-team parlay. "The punter from Dublin told William Hill UK that he wouldn't have placed the bet, if he had known [that it had never happened before]."
posted by Etrigan at 03:09 PM on August 13, 2015
It's funny that ESPN felt it necessary to cite a source for the odds of a coin coming up heads 15 times in a row. I'm bad at stats, but even I could puzzle that one out.