Remster 24 #26 October 8, 2003 QuoteI think alot of you are missing what this is saying. It is not saying that YOU PERSONALLY can go 20,000 jumps without dying, it is saying that every 20,000 jumps all across the us or world or whatever, someone dies. In otherwords, there could have been 19,999 safe jumps and that next jump you make will statistically increase your odds of dying. I dont buy into it, but thats what it is saying. sigh.... here we go again with stats.... No... what it means is that statistically, there is 1 death for every 20,000 jumps (if these numbers are right). So on every jump, you have 1/20000 chances of dying. If you make 19,999 jump, on your next one, you STILL have 1/20000 chances of dying. (if every skydive is unrelated and random* which they probably are not, but you get the point I hope) Every skydive increases your chance of dying. But the chance of dying on your next jump will always be the same (on a statistical level only of course). If you flip a coin and end up heads 10 times in a row, what are the odds the next one will the heads again? PS: I'm not sure what the exact english term is for this as my stats classes were in french... someone can let me know?Remster Quote Share this post Link to post Share on other sites
kelpdiver 2 #27 October 8, 2003 You said it quite accurate. I think the phrase in English would be "prior events have no bearing on future probabilities." And the chance is of course not consistent. AFF1 students have two JMs, a simple plan, and very good focus, if not any experience with handling mals. Reasonably experienced jumpers start to lose a bit of that focus - don't fear death as much. And then veterens have survived that period and enjoy better odds, unless they are also increasing their degree of difficulty substantially. Now you can take that 1/20000 and ask the question, how many jumps can I do before it is 50% likely that I'll die? The answer is slightly less than 10,000 - you multiple 19999/20000 against itself until you hit .500. But then again, people win the lottery every week and that's a 1:50mil shot. Does anyone know how the USPA derived the 3 mil jump figure? Is it all confirmed counts from DZ or member surveys, or did they add a fudge factor for non USPA jumping? I'd be surprised if the true count were more than 25% lower than it, and could easily be higher. So it's probably at least 1:75000 and perhaps as high as 1:150000. Quote Share this post Link to post Share on other sites
Remster 24 #28 October 8, 2003 Quote"prior events have no bearing on future probabilities." naaaa. I meam the techy term you must always quote when providing odds... never mind... you get the jitz of it. I guess independant and random is close enough....Remster Quote Share this post Link to post Share on other sites
fundgh 0 #29 October 8, 2003 What it could mean: 1) If there are 20 people on the otter and each has 1000 jumps .....Somebody will die on that load. 2) If you are doing a AFF jump there are 3 people in your jump.... it is 3 times as likely that somebody will die. 3) If 20,000 jumps (world wide) are carried out on a saturday...somebody in the world will die. 4) If time travel were possible, and you went back and did the same jump 20,000 times...you would die. Stats are fun, and dangerous, use them wisely! Maybe there should be a BSR on what kind of statistic one is qualified to use!...FUN FOR ALL! Quote Share this post Link to post Share on other sites
Casch 0 #30 October 8, 2003 1)No, someone COULD die on that load, just like on every previous jump and every jump to follow 2)I believe so 3)No, someone in the world COULD die 4)No, if you survived the jump the first time and every single variable was exactly the same each time you "relived" the jump, you're garunteed to live. Even though you get closer to the 20,000 jump mark, each and every jump has the exact same probability of death (considering each jump is the same type of jump). And in reality, each jump has a very slightly smaller chance of death because of gained experience. Saying 1 jump in 20000 ends in death is a terrible way to put it. A better way to put it is every jump has a 1/20000 percent probability of resulting in death. Quote Share this post Link to post Share on other sites
kelpdiver 2 #31 October 9, 2003 QuoteWhat it could mean: 1) If there are 20 people on the otter and each has 1000 jumps .....Somebody will die on that load. 2) If you are doing a AFF jump there are 3 people in your jump.... it is 3 times as likely that somebody will die. 3) If 20,000 jumps (world wide) are carried out on a saturday...somebody in the world will die. 4) If time travel were possible, and you went back and did the same jump 20,000 times...you would die. Stats are fun, and dangerous, use them wisely! yes, but fortunately your's are not accurate. Your hypothetical characters have a chance of living. 1- probability that 1 or more of the 20 will die is 1.0 - (19999/20000)^20, or .000999, or just less than 1 in 1000, just as we'd expect with 20 people at 1 in 20000. Prior jumps don't matter - we know that they survived them all. 2 is true, though the odds for each person doesn't increase. 3- 1.0 - (19999/20000)^20000 = .632. 63% likelihood of 1+ fatalities. 4- if you believe in chaos theory - that even doing the exact same jump again could result in different results, then the answer is the same as #3. But if you go with the followup posting that you're already succeeded and are just repeating it, you know you will survive. (cynics might point out that the airspace would be getting pretty crowded long before the last jump) If you rephrased #1 to what is the likelihood that a group of 20 new jumpers would make it to 1000 jumps, it too would be only 37%. Quote Share this post Link to post Share on other sites
Jayruss 0 #32 October 9, 2003 you know 46% of all statistics are made up on the spot __________________________________________________ "Beware how you take away hope from another human being." -Oliver Wendell Holmes Quote Share this post Link to post Share on other sites
schattenjaeger 0 #33 October 9, 2003 Judging from his last sentence, I think he wasn't being serious, but making a point about abusing stats... Quote Share this post Link to post Share on other sites
Casch 0 #34 October 9, 2003 Oh...well according to another thread I'm an impatient person...so I didn't get that far. My bad Quote Share this post Link to post Share on other sites
kallend 1,623 #35 October 9, 2003 Quoteyou know 46% of all statistics are made up on the spot That was funny the first time I heard it - some 35 years ago.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
kallend 1,623 #36 October 9, 2003 QuoteYou said it quite accurate. I think the phrase in English would be "prior events have no bearing on future probabilities." You need to be careful with that concept, after all, the best predictor of future events IS what happened in the past, usually summarized: "past is prologue". That's how we predict the date of the next eclipse, the full moon, the hurricane season, the return of Halley's Comet, the best time to get flu shots, etc. What you are referring to is statistical independence.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
JeffD 0 #37 October 9, 2003 So where do low hook turns , canopy collisions, misjudgement etc...come in to play? say 50% of the deaths are user related error and not equipment failure, then I believe that you have a lot better than 1/20,000 chance. Quote Share this post Link to post Share on other sites
kallend 1,623 #38 October 9, 2003 QuoteSo where do low hook turns , canopy collisions, misjudgement etc...come in to play? say 50% of the deaths are user related error and not equipment failure, then I believe that you have a lot better than 1/20,000 chance. ? The statistics (assuming they are accurate) refer to the population as a whole. Any individual can improve or worsen her chance of death by changing her behavior. Just like with AIDS. Unfortunately we do not have good enough data to know for sure what the effects of certain behaviors may be in skydiving. For example, it is often assumed but is actually unproven that flying a highly loaded canopy when you have low jump numbers increases the odds that you will become a fatality statistic. We simply don't have the data to confirm or disprove this assumption, and we are not even trying to collect the data as far as I know. So, in the absence of more detailed data, just go with the averages.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
NoShitThereIWas 0 #39 October 9, 2003 I think the term you are trying to get at is independent events. Odds have to do with the ratio of the probability of one event occuring/probability of alternative events or a comparison of two probabilities. For example, if I asked you what are the odds for picking a heart card out of a deck of cards? We all know that to be 1/4 but to calculate that statistically, you would say that there are 13 events that would fit/52 total cards = 1/4. Someone was right when they spoke about flipping a coin. Every time you flip a coin you still have a 50% chance that it will land heads "or" tails. If you flip a coin once and it lands heads, your odds don't change the next time you flip the coin to give you a higher odds of getting tails the next time around. Your probability of flipping tails is still 50% or 1/2. This is because flipping the coin is an independent event and does not affect the outcome of future "flips". Prior events can have bearing on future probabilities if you set them up that way. You would simply use the rules of probability to figure it out. If you want to calculate the probability of a sequence of events occuring, like the probability of flipping heads 5 times in a row, you would take the probability of flipping heads which is 1/2 and raise it to the fifth power. This gives you an answer of 1/32 or .03125 chance of those events occuring in sequence. So hypothetically if 1 out of 20,000 skydives statistically has resulted in death, based on the data and numerical information already accumulated, every time a skydive is made there is a statistical chance or probability of .00005 that your skydive could result in death. Also, statistics are just trends or like historical values. There's nothing to say that they are engraved in stone. There are also ranges and standard deviations from the "norm" that take place and should not be overlooked.Roy Bacon: "Elvises, light your fires." Sting: "Be yourself no matter what they say." Quote Share this post Link to post Share on other sites
gremlin 0 #40 October 9, 2003 The interesting thing would be to see how the stats varied - both between countries with different safety standards and over time as new safety measures came in. For example has the cyprus saved more lives than have been lost with the rise of the hook turn. And if in doubt don't jump with someone who has about 40,000 jumps as it is 50:50 which one of you will go in on the next jump I'm drunk, you're drunk, lets go back to mine.... Quote Share this post Link to post Share on other sites
mikemc 0 #41 October 9, 2003 In the original post of this thread its refers to a footnote stating info came from USPA. Surely every jump is logged by them? The BPA must log drop numbers? Every lift is manifested, records are kept whose says these numbers are not passed onto the powers that be? I dont want to start conspiracy theories but maybe "people" dont want the actual numbers released. Quote Share this post Link to post Share on other sites
Jayruss 0 #42 October 9, 2003 QuoteQuoteyou know 46% of all statistics are made up on the spot That was funny the first time I heard it - some 35 years ago. yeah that's a problem for someone still in his early 20's __________________________________________________ "Beware how you take away hope from another human being." -Oliver Wendell Holmes Quote Share this post Link to post Share on other sites
Remster 24 #43 October 10, 2003 QuoteIn the original post of this thread its refers to a footnote stating info came from USPA. Surely every jump is logged by them? Not even close..... its an estimate. DZs do not have to report how many jumps they made.Remster Quote Share this post Link to post Share on other sites
Newbie 0 #44 October 10, 2003 stats in skydiving should be taken with a larger than usual handful of salt as far as im concerned. Im new to this but reading the history it's obvious that you can do everything right and still die. When Murphy strikes, that doesn't have much to do with statistics. Realise that you are not "safe" because you are nowhere near a magical number; rather, be vigilant and practice your reserve drills on the ground, in the plane and just before exit everytime you go up, and think that the next jump will yield a mal and you will need to be calm and react to that situation. That should help you out when the shit hits the fan, and if all fails and Murphy shows up, well you went out doing what you love, that's the way i look at it. "Skydiving is a door" Happythoughts Quote Share this post Link to post Share on other sites
kallend 1,623 #45 October 10, 2003 Quotestats in skydiving should be taken with a larger than usual handful of salt as far as im concerned. Im new to this but reading the history it's obvious that you can do everything right and still die. When Murphy strikes, that doesn't have much to do with statistics. Realise that you are not "safe" because you are nowhere near a magical number; rather, be vigilant and practice your reserve drills on the ground, in the plane and just before exit everytime you go up, and think that the next jump will yield a mal and you will need to be calm and react to that situation. That should help you out when the shit hits the fan, and if all fails and Murphy shows up, well you went out doing what you love, that's the way i look at it. I really don't understand this attitude. You could say exactly the same about any epidemiological study. It's possible to get lung cancer even if you don't smoke, vegetarians die of heart attacks, and it's possible to die in a car crash even if none of the parties has been drinking alcohol --- Murphy strikes in many places. However, statistics are a good indicator of what's happening to the population as a whole.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
Newbie 0 #46 October 10, 2003 QuoteQuotestats in skydiving should be taken with a larger than usual handful of salt as far as im concerned. Im new to this but reading the history it's obvious that you can do everything right and still die. When Murphy strikes, that doesn't have much to do with statistics. Realise that you are not "safe" because you are nowhere near a magical number; rather, be vigilant and practice your reserve drills on the ground, in the plane and just before exit everytime you go up, and think that the next jump will yield a mal and you will need to be calm and react to that situation. That should help you out when the shit hits the fan, and if all fails and Murphy shows up, well you went out doing what you love, that's the way i look at it. I really don't understand this attitude. You could say exactly the same about any epidemiological study. It's possible to get lung cancer even if you don't smoke, vegetarians die of heart attacks, and it's possible to die in a car crash even if none of the parties has been drinking alcohol --- Murphy strikes in many places. However, statistics are a good indicator of what's happening to the population as a whole. They certainly are a good indicator, i'm not disputing that, but as far as im concerned there is no way to know what life will throw at you, and therefore they remain nothing more than an indicator. The most important thing is to not be lulled into a false sense of security by the fact you aren't anywhere near 20,000 jumps or what have you. Vigilance on every jump, regardless of what the statistics say, is more important than what the statistics say, is what im trying to say. "Skydiving is a door" Happythoughts Quote Share this post Link to post Share on other sites
mikemc 0 #47 October 10, 2003 What I am I saying and what I think others are saying is...what are the actual numbers??? Not, am I going to die on the next jump? Quote Share this post Link to post Share on other sites
gerryfuss 0 #48 October 10, 2003 The truth is that as a whole the odds are what they are. 1 in 20000 was the odds quoted of dying. Lets just assume that these are the correct odds for this discussion. There are too many variables to generalize this to each individual . Everyone actually has their own odds. One individual may be doing his first jump at a DZ with the worst safety record in the country, with gear that should have long been retired,poor instruction, an old aad that was not even turned on .... etc. The chance of this individual biting the dust is quite a bit higher than lets say an individual who is very saftey concious both in freefall and under canopy ,has a cypres 2 , gear in excellent condition just checked out by a an expert rigger ......etc. You take all these people with different probabilities and figure out the average probability of death as a whole for the group and you will end up at 1 in 20000 There are things you can do to increase your odds but nothing you can do to make your odds zero, (and you can't time travel) so anything can happen to anyone at anytime. Quote Share this post Link to post Share on other sites
neilly 0 #49 October 10, 2003 just for the hell of it, if someone dies on jump 10000, can they ask for a recount or refund,lolFly like an aardvark Quote Share this post Link to post Share on other sites
kallend 1,623 #50 October 10, 2003 www.amazon.com/exec/obidos/tg/detail/-/0809058405/qid=1065803809/sr=1-2/ref=sr_1_2/103-2982970-6267859?v=glance&s=books... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
