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[quote=Anonymous][quote=Anonymous][quote=Anonymous][quote=Anonymous][quote=Anonymous][quote=Anonymous][quote=Anonymous]Your explanation "using math" assumed that you had an equal chance of getting into each school (that each school has the same number of open spots and each is just as popular as each other).  That is not the case.  If you were truly such a math whiz you'd understand that.[/quote]

It is the exact same.  If you disagree, please explain it mathematically.[/quote]

Sure.  Let's say that there are 5,000 kids, applying for 500 places.  That gives them a 1:10 chance of getting a spot somewhere under the common lottery.  Let's assume that none have siblings, are IB or have proximity preference, just to make it simpler.

Now let's say that they applied to the following schools using the old system:

school 1 - 300 kids apply and there are only 30 places - odds are the same 1:10
school 2 - 100 kids apply and there are 25 places - YOUR ODDS ARE 1:4 BINGO, your odds are increased from those of the common lottery (for that school at least)
school 3 - 500 kids apply and there are only 10 places - your odds are worse than under common lottery (for that single lottery) = 1:50

etc, etc. 
[/quote]

I'm just bumping this because all of those who claim that they are such experts in statistics have ignored it.  Please take a look and tell me why you are ignoring this.  Thanks.[/quote]

Because there are different numbers of people applying to different schools.  If under the old system, only 100 kids applied to a school with 25 spots (school 2 in the above example), then logically under the new system only 100 people would have that school in their list of 12 under the new system.  Your odds for that school would still be 1:4 for that school under the new system.  Everyone is confusing their odds from before the lottery is run, when the odds are the same under either system, compared to their odds after the lottery is run.  Your odds after the lottery is run are different under the two systems, but that's because you have cycled through 95% of the probabilities by running it all at once.  Under the old system you only got through maybe 70% of the probabilities (complete guesses!) because of all the shuffling that went on.  The difference now is the final answer comes much quicker.

If I may make an analogy, it's like saying a quarterback has a 70% completion percentage of the receiver catching the ball.  That's an overall percentage on every play.  But if you evaluate the odds of an individual throw [b]while the ball is in the air[/b], you have a lot more information and the probabilities will change.  You would be able to tell at that point how well covered the receiver was, if the ball looked like it was too high or too low, etc.  The odds would be much closer to 0 or 100% at that point.  Under the old system it was kind of like that.  Under the new system it's much more binary- you have the overall odds at the beginning, and you pretty much jump to the point where the ball is caught or not.  So it [b]seems[/b] like one might have had better odds under the old system, because you were looking at the odds more along the playing out of the probabilities.[/quote]

Different "dumb-feeling" PP, I appreciate you really trying to explain this!  Still though, even your football analogy isn't helping me understand why overall my odds are exactly the same (according to you) in a given year of applying, whether I have only one chance at a good number vs, 12 chances.  Maybe I'll never understand without taking a statistics class, but I'm still not seeing your point right now.[/quote]

Because you have one chance at a good number when there are let's say 1000 applicants and 100 spots, versus let's say 10 chances (because it makes it easier) where there are 100 applicants at each of the 10 schools and 10 places at each.  In each scenario your odds are 1:10.  In reality the odds vary slightly by school but because the overall number of spaces and overall number of applicants is the same in either scenario (in reality they vary by year, but let's assume that both systems were run in a single year and people made the same decisions) but the overall odds of getting in somewhere remain the same.[/quote]

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