Draw odds??.... Math for Dummies

[Dave32g]

like many of you, i have my name in several drawings across the western US.
my question is, how do i find the odds of being drawn at least once?
for example: ( to make it easy) lets say I'm in 10 drawings across 5 states (5 deer 5 elk ) odds are exactly 10% chance to draw in each drawing .
what are the odds im drawn at least once? what is the formula used to figure this out?

thanks in advance
Dave

 

[Pelican]

Probabilities multiply. The formula is (1-(the probability of drawing)^(number of draws)
So (1-0.1)^10 or 0.9^10 or 0.9x0.9x0.9x0.9x0.9x0.9x0.9x 0.9x0.9x0.9. This gives you the probability of NOT drawing any of you tags and equals ~35%. So your odds of being successful in one of your ten drawings is ~65%. If you applied for 5 draws with 10% success, it would be 0.9^5. At least I think that’s correct.

 

[375H&H]

50:50, either you draw or you don’t. Surprisingly, most of life is 50:50.

 

[LopeHunter]

Probabilities multiply. The formula is (1-(the probability of drawing)^(number of draws)
So (1-0.1)^10 or 0.9^10 or 0.9x0.9x0.9x0.9x0.9x0.9x0.9x 0.9x0.9x0.9. This gives you the probability of NOT drawing any of you tags and equals ~35%. So your odds of being successful in one of your ten drawings is ~65%. If you applied for 5 draws with 10% success, it would be 0.9^5. At least I think that’s correct.

1 - (odds do not draw tag 1 x tag 2 x tag 3....tag N) gives you the odds you draw one or more tags. Some will draw more than 1 tag in that population that is not part of the "will not draw a tag."

 

[brownbear932008]

I'm a math dummy don't ask me. But the odds of me drawing back to back years in my NM elk tag were slim and none and guess what I'm headed back to NM high county in October. Just apply and see what falls out someone has to get the tag.

 

[ImBillT]

Pelican has it right for the case you asked about, which was that all the hunts had exactly 10% draw odds.

(1-.1)^10 is shorthand for (1-.1)(1-.1)(1-.1)(1-.1)(1-.1)(1-.1)(1-.1)(1.-1)(1-.1)(1-.1). If you had ten hunts with varying odds, you would just multiply the probability of not drawing each individual tag, and that would be the probability of not drawing any tags. For example, if two elk tags had 6% and 4% odds and two deer tags had 11% and 14% odds the probability of not drawing any of them would be (1-.06)(1-.04)(1-.11)(1-.14) or 69.1%. The odds of drawing at least one would be 31.9%.

 

[jvanhoy]

Not to derail this question but I’ve been wondering about how to calculate point creep. Let’s say a tag has trended a 15% drop each year. Started 80% at 2 points minimum dropped to 65% 50, 35, 20. Then it takes a big jump to 3 points minimum at 75%. Is this big jump to the next point level due to having a higher percentage of people in the 2 point pool not drawing the year prior and it should slow back down to around the 15 percent normal drop? That’s what I’m hoping but have no clue. Sorry if this makes no sense haha.

 

[AggieOutlaw]

50:50, either you draw or you don’t. Surprisingly, most of life is 50:50.

You are describing binary events (outcomes are either success or failure). The probability is definitely not 50/50. Although I think I understand your sentiment, most of life's binary events are far from 50/50.

 

[jvanhoy]

Not to derail this question but I’ve been wondering about how to calculate point creep. Let’s say a tag has trended a 15% drop each year. Started 80% at 2 points minimum dropped to 65% 50, 35, 20. Then it takes a big jump to 3 points minimum at 75%. Is this big jump to the next point level due to having a higher percentage of people in the 2 point pool not drawing the year prior and it should slow back down to around the 15 percent normal drop? That’s what I’m hoping but have no clue. Sorry if this makes no sense haha.

Anybody? Am I way off track with this?

 

[npaden]

Not to derail this question but I’ve been wondering about how to calculate point creep. Let’s say a tag has trended a 15% drop each year. Started 80% at 2 points minimum dropped to 65% 50, 35, 20. Then it takes a big jump to 3 points minimum at 75%. Is this big jump to the next point level due to having a higher percentage of people in the 2 point pool not drawing the year prior and it should slow back down to around the 15 percent normal drop? That’s what I’m hoping but have no clue. Sorry if this makes no sense haha.

You could do some type of scatter graph that would point you in the general direction, but there are so many things that can influence applications and in units with a relatively low number of tags it can really wreck havoc.

I've researched tags before that currently take 7 or 8 points that when I'm doing my google searching I find old posts on some forums complaining that those units take 2 or 3 points to draw. Doing the math someone that was 1 point behind could have applied every year and never caught up. Generally that is due to some type of publicity where someone shot a big animal in that unit or a TV show was filmed in that unit or something. Sometimes there are just a few tags available for a certain area that for some reason or another becomes popular and it is easy to overload a particular unit with apps.

The problem with guessing point creep is the fact that so many people just buy points and don't apply for tags. It becomes almost impossible to guess when those folks are going to step off the sidelines and apply.

 

[Dave32g]

Pelican has it right for the case you asked about, which was that all the hunts had exactly 10% draw odds.

(1-.1)^10 is shorthand for (1-.1)(1-.1)(1-.1)(1-.1)(1-.1)(1-.1)(1-.1)(1.-1)(1-.1)(1-.1). If you had ten hunts with varying odds, you would just multiply the probability of not drawing each individual tag, and that would be the probability of not drawing any tags. For example, if two elk tags had 6% and 4% odds and two deer tags had 11% and 14% odds the probability of not drawing any of them would be (1-.06)(1-.04)(1-.11)(1-.14) or 69.1%. The odds of drawing at least one would be 31.9%.

Thanks for all the input.
ImbillT you made it simple.

 

[elkduds]

the probability of not drawing any of them would be 69.1%. The odds of drawing at least one would be 31.9%.

Did you mean 30.9%, as in 100% - 69.1% = 30.9%?

 

[LostinOregon1]

Not to derail this question but I’ve been wondering about how to calculate point creep. Let’s say a tag has trended a 15% drop each year. Started 80% at 2 points minimum dropped to 65% 50, 35, 20. Then it takes a big jump to 3 points minimum at 75%. Is this big jump to the next point level due to having a higher percentage of people in the 2 point pool not drawing the year prior and it should slow back down to around the 15 percent normal drop? That’s what I’m hoping but have no clue. Sorry if this makes no sense haha.

The most important thing to look at is the number of folks in the point pool that didn't draw the tag last year. An example of this is that last year everyone with 12 points drew a tag. There were 50 tags. So most people think, I am in with 12 points this year. However, last year there were 200 people who put in with 11 points who now have 12 points. So 50 ( about 25% if factors 2 and 3 listed below don't affect draw odds) will actually draw this year and points to guarantee the tag will increase for 3 years until that pool of 200 people are eliminated or draw the tag.

Second factor to consider is how many folks were sitting on the sidelines, not applying that year waiting for the right dates or right year. Impossible to figure out, however the later dates in Colorado deer seasons are often quite predictable with higher numbers of folks applying. Those that jump in above the minimum will eliminate tags available from the 50 above and further dropping odds below

Third factor I consider is the "fool factor", meaning if a unit hits a publication or the hunting websites you have additional creep and the only way to figure this out is to be diligent in your research. Examples of this happening this year will be evident in Colorado unit 67 draw odds. Hope this helps,

Rich

 

[ImBillT]

Did you mean 30.9%, as in 100% - 69.1% = 30.9%?

Yep