Still neck division

[jchris98]

(01-16-2014 04:23 AM)amoffett11 Wrote:  This is the same as the classic Birthday problem: given 25 people in a room, what are the odds that at least 2 of them have the same birthday. People are usually quite surprised to find that the odds are slightly higher than 50% that 2 people will be born on the same day.

Given the number of division there are, and the number of seasons now that divisions have been generated (4), the odds are very high that we'd get at least one collision. I'd bet that there's been some before and it's just gone unnoticed.

Are you sure?

[amoffett11]

(01-16-2014 09:06 AM)jchris98 Wrote:  

(01-16-2014 04:23 AM)amoffett11 Wrote:  This is the same as the classic Birthday problem: given 25 people in a room, what are the odds that at least 2 of them have the same birthday. People are usually quite surprised to find that the odds are slightly higher than 50% that 2 people will be born on the same day.

Given the number of division there are, and the number of seasons now that divisions have been generated (4), the odds are very high that we'd get at least one collision. I'd bet that there's been some before and it's just gone unnoticed.

Are you sure?

Sure about what? The birthday thing?

[jchris98]

Yeah, that doesn't sound right

[lawtai]

http://en.wikipedia.org/wiki/Birthday_problem

Looks like you only need 23 people to hit 50%.

[amoffett11]

(01-17-2014 02:14 AM)lawtai Wrote:  http://en.wikipedia.org/wiki/Birthday_problem

Looks like you only need 23 people to hit 50%.

Ya, whenever I hear the example, it's always 25, but probably because that's just an even number.

I remember having this discussion with my brother years and years ago, he didn't believe it either, so we started looking at baseball teams (every team 25 players on its roster), we went through about 16 teams and 10 or 11 teams already had two players with the same birthday, so we stopped.

[Mag!cGuy]

I read an article about it, and there was the mathematic proof of this, so I could only believe it

[[PETA] Doodat]

Pretty sure it's about probabilities:
Need to find the percentage of no people have birthdays together (this is continuing to assume that no two people have the same birthday)
For 1 person, there is 365/365
For 2 people, I would say 364/365 to keep it simple, although the fraction is much weirder than that due to leap years.
3 people: 364/365 * 363/365
4 people: 364/365 * 363/365 * 362/365
5 people: 364/365 * ... * 361/365
And so on.
Even for 10 people: already ~12% chance that 2 people will have the same birthday. (because ~88% chance that they will not have the same birthday)

[TheGreatErenan]

Yes, Doodat has it right.