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What are the odds? .1%?

PostPosted: Sun Oct 28, 2012 1:36 am
by chrisfu
Any statisticians out there?

In my mystery 70's league, my team stats 39 games into the season, says that the #of rolls against my pitchers is

809 hitters cards, 689 pitchers cards. It should be somewhere close to 50/50, obviously.
According to my basic stats class, die rolls follow the normal curve, with an SD of .5. With 1498 rolls I am expecting 749 hitters/749 pitchers with a SD of 19. So, 809 hitters is over 3 SD's away from the expected value, which should occur .1% of the time. Am I calculating this incorrectly? My pitchers are getting lit up and it doesn't seem that they should be that bad.
It seems highly improbable that this should happen.

Re: What are the odds? .1%?

PostPosted: Sun Oct 28, 2012 4:44 am
by franky35
I'm seeing that for almost every team, there are significantly more hitter card results as compared to pitcher card results. Is this because fielder(x) results are not counted on the pitcher card?

Re: What are the odds? .1%?

PostPosted: Sun Oct 28, 2012 10:56 am
by chrisfu
That doesn't seem true in my league, most die roll counts are close to 50/50, except for my pitcher rolls.

Re: What are the odds? .1%?

PostPosted: Sun Oct 28, 2012 12:32 pm
by franky35
I was wrong. I summed my 70s league and its ptichers 4096/4144 P/H and hitters 4066/4100 P/H.

Re: What are the odds? .1%?

PostPosted: Sun Oct 28, 2012 1:22 pm
by coyote303
I'd love to have a statistics expert state the odds because my best guess is around 6 percent.

Re: What are the odds? .1%?

PostPosted: Mon Oct 29, 2012 12:45 pm
by kenhutchings
I would have to dust off some of the books from statistic classes that I took in school in order to get an exact figure, but even though the numerical difference appears to be significant, in reality the percentage of the higher number (809) amounts to 54% of the total rolls (1,498). In my opinion, that seems to be within reason for a random distribution. Or another way of looking at it is that if everything was exactly even, there would have been 749 rolls on each card. Dividing 809 by 749 results in 1.08, or that the results on one card is occurring 8% more than the other card.

Re: What are the odds? .1%?

PostPosted: Wed Nov 21, 2012 11:50 pm
by Terry101
Chrisfu,

The odds are 1 in 1000 that in a series of 1498 trials, given a probability of 50/50 that 809/1498 would occur. Your initial calculation was correct.