Community

 
Jump Menu:
Post Reply
Page 11 of 14  •  Prev 1 ... 9 10 11 12 13 14 Next
6 months ago  ::  Nov 29, 2012 - 5:09PM #101
bubba0077
  • Volunteer Community Lead
  • blame me for the weather
Date Joined: Feb 27, 2002
Posts: 9,834

Nov 29, 2012 -- 4:27PM, urbanjedi wrote:

I was a stats major in college and I do understand that the probability of any single coin-flip is always 50/50. I was simply pointing out that over 100 flips that it should be 50/50 heads/tails so if you know that 20 of those flips are heads then you know that statistically speaking that 50 of the remaining 80 flips should be tails so if you bet tails for the next 80 flips then statistically you should win. Now because it is 50/50 and it might take 10000 flips to even out (instead of 100), it isn't a "proven" strategy to beat the system. That and the fact that there is no skill involved. The player has no influence.



I rarely challenge people here on what they claim about their lives, but I'm calling bull. No stats major would make such a basic mistake, let alone repeat it.

Magic Online Volunteer Community Lead. • Also assisting the Paper Magic area for the time being.
I'm trying to make my official VCL posts in purple

You posted saying my thread was moved/locked but nothing happened.      Spoiler: Show
Unfortunately, VCLs do not currently have the tools necessary to take moderation actions directly. VCLs submit their actions to ORCs, who then actually perform the action. This processing can take between a few minutes and several hours, depending on how busy/attentive the ORCs are.


If you see something that needs VCL attention, please use this thread (MTGO) or this thread (paper) to make a request and a VCL will look at it as soon as possible.  CoC violations should be reported to Customer Service using the "report post" button. Please do not disrupt the thread by making requests of either kind in-thread.

General MTGO FAQ


Yes, the Shuffler is Random!
The definitive thread on the Magic Online shuffler.

Magic Math Made Easy
Draw probabilities, Swiss results, Elo ratings and booster EV

Event EV Calculator
Calculate the EV for any event with a fixed number of rounds and prizes based on record

Dual means two. A duel is a battle between two people. Lands that make two colors of mana are dual lands. A normal Magic battle is a duel.

Thanks to PhoenixLAU for the awesome avatar!

QuotablesSpoiler: Show
"While a picture is worth a thousand words, each lolcat actually produces a negative wordcount." -Ith

"I think "Highly Informed Sarcasm" should be our Magic Online General motto." -Ith

"Sorry, but this thread seems just like spam. TT is for off-topic discussion, not no-topic discussion."
-WizO_Kwai_Chang

"Stop that! If you're not careful, rational thinking may catch on!" -Sax

"... the only word i see that fits is incompitant." -Mr44 (sic)

"You know a thread is gonna be locked when it gets to the hexadecimal stage." -Gathion

"It's a good gig" - Gleemax

"I tell people often, if you guys want to rant, you've certainly got the right to (provided you obey CoC/ToS stuff), and I don't even really blame you. But if you see something you think needs changing a well thought-out, constructive post does more to make that happen." - Worth Wollpert
Quick Reply
Cancel
6 months ago  ::  Nov 29, 2012 - 7:05PM #102
MTGKaioshin
  • Sacrificial Lamb
Date Joined: Feb 8, 2007
Posts: 7,461
Yeah.....I think we can all agree here that that is just wrong.
NSFW Show
Taken BEFORE a single CC2010 match was played.


My forever unfinished blog of the 2010 MTGO Community Cup: if you're ever bored...
1st Annual WizardsCommunity MTG Holiday Card Exchange
Quick Reply
Cancel
6 months ago  ::  Nov 29, 2012 - 9:33PM #103
urbanjedi
Date Joined: Aug 17, 2007
Posts: 829
Well, it seems I don't do very well explaining things but this will be my last try.

It all depends on what you determine to be a good enough sample size.  But if I tell you the odds of something and then tell you what I have observed after a sample size of X, you should easily be able to tell me what should (statistically) happen over the next X samples.   So if I said a coin flip is 50/50 and I have flipped it 817 times and 600 times it came up heads and 217 times it came up tails, you should be able to tell me that if I flipped the coin another 817 times that it should even out (maybe not entirely flip but at least even out) with more tails than heads because after 1634 flips it should be closer to 50/50 than my 73% heads has shown.  Therefore with that knowledge if I were to bet on the 2nd set of 817 flips then I should bet tails.  Unless of course you don't think that 1634 is a large enough sample size for coin flipping.  This only works because I know what the initial sequence was and I know what the overall (absolute) probability is.

Now we all know that in "reality" if I flipped a coin 817 times I would really have 400 ish of each type and the actual numbers I got would in likelihood fall within 1-3 standard deviations based on the number of flips.

I was just using the extreme case (as others have) to basically show that if I know a probability and I know what has come before then I can somewhat predict what will come after.  Very similar to how MTG players predict the odds they will draw a land (or any card).  I have drawn 6 so far and have 11 left in my deck. 

And yes, the probability of any 1 coin flip is and always will be 50%, but depending on what sample size you are willing to call sufficient you can "play the odds" and predict what will happen if you know what has already happened (but only in some of the more extreme cases) and never over an individual coin flip.
Quick Reply
Cancel
6 months ago  ::  Nov 29, 2012 - 9:57PM #104
jacobsldr
Date Joined: Dec 14, 2008
Posts: 130

Nov 29, 2012 -- 9:33PM, urbanjedi wrote:

...... and never over an individual coin flip.




and thus since each individual coin flip is independent of anything prior, no predictions can be made about future coin flips outside of the 50/50 probability, regardless of what previously occurred over any sample size.


Quick Reply
Cancel
6 months ago  ::  Nov 30, 2012 - 12:22AM #105
nushae
Date Joined: Mar 20, 2003
Posts: 3,712
urbanjedi, please stop posting, it hurts.
Quick Reply
Cancel
6 months ago  ::  Nov 30, 2012 - 2:48AM #106
simongoertzen
Date Joined: Sep 5, 2012
Posts: 46
urbanjedi, you a wrong, and I assume it's because of a misinterpretation of the Law of large numbers. This misinterpretation is also known as the Gambler's fallacy.
Quick Reply
Cancel
6 months ago  ::  Nov 30, 2012 - 3:40AM #107
Papp76
Date Joined: Nov 25, 2012
Posts: 8
Yeah, the coinflip example is completely wrong. If you would however change it to red cards and black cards in a normal card deck, where you actually KNOW the end result, that is a different story. Then it will obviously get more likely to draw a black card in the end, the more red card that was being drawn earlier on.
Every single coinflip is always going to be 50/50, and the probability of each flip won't change based on what has happened in the past since you don't KNOW what the results will be after your 817 flips. You can predict that it will be 50/50, but randomness might take the end result somewhere else.  
Quick Reply
Cancel
6 months ago  ::  Nov 30, 2012 - 7:54AM #108
Zlehtnoba
Date Joined: Mar 26, 2004
Posts: 882

Nov 29, 2012 -- 12:40PM, silentbobus wrote:

Nov 29, 2012 -- 9:16AM, Zlehtnoba wrote:

Well, the classic answer, which I already quoted to you in another context, is that the previous flips don't matter a bit (unless, of course, the coin is rigged). So it doesn't matter at all what you bet on, your chances are the same anyway.

This is most commonly talked about in discussions of lottery.

And about our arguments: I, and many others (Nushae for example), argue with your assumptions, not with your data. I feel your model is flawed, since it does not take into account important factors which influence the win/loss percentages. About the only way to resolve our argument is by experiment: change the rule, and see what happens.




That is the answer that most people with a statistical background give. The coin has no memory of previous flips, so either side is equally likely to come up on the next flip. But that answer is wrong. The naive answer of 'bet on heads' turns out to be correct. Because in the scenario described there are 3 possibilities:

1) The coin is fair, but happened to flip 9 heads in a row by chance
2) The coin has two heads, every flip will come up heads
3) The coin has a heads and a tails but is weighted in such a way that causes it to come up heads more often than tails

In scenario one it doesn't matter which side you bet on, but in scenarios two and three the correct answer is 'bet of heads'. Since betting on heads will never hurt you, and can potentially help, it is the correct answer.




Since we're fantasizing: the lottery says bet on tails. Many people will be thinking like you did above, but if the coin is random, then tails are equally likely, but less people bet on it, so your winnings are bigger. In lottery, it's very unlikey you win anyway, so if you do strike lucky, go for the psychologically unappealing numbers.

And I won't even complain that you took a well-known example where we all make hidden assumptions, and then proposed a scenario that does not include to those assumptions, since I saw that one coming. You were talking about real-life coing tossing with no additional data about the coin, I was talking about the statistical coin-toss problem.

50. Doesn't hurt. Yet.
Quick Reply
Cancel
6 months ago  ::  Nov 30, 2012 - 12:47PM #109
silentbobus
Date Joined: Jun 15, 2009
Posts: 7,518

Nov 30, 2012 -- 7:54AM, Zlehtnoba wrote:

And I won't even complain that you took a well-known example where we all make hidden assumptions, and then proposed a scenario that does not include those assumptions, since I saw that one coming. You were talking about real-life coing tossing with no additional data about the coin, I was talking about the statistical coin-toss problem.




Perhaps that's why I find RNG discussions on here so trying, because if I flipped a coin 9 times and saw it come up heads 9 times I would jump immediately to questioning whether the coin was fair. While most other people on here would assume the coin is fair, and that they just happened to witness a 1 in 512 occurance.

And to those people I say:

"Sorry, I forgot to introduce myself. I'm Daniel D'Arby and this is my cat."

Quick Reply
Cancel
6 months ago  ::  Nov 30, 2012 - 1:06PM #110
cretonic1
Date Joined: Jul 10, 2007
Posts: 1,900
Having been halfway observant of my tactics for a few weeks now I would say that mulliganing down to 6 usually has a better outcome than keeping a hand full of high cost mana and 1 land.  6 cradz doesn't seem to make much more difference than 7.  5 cradz seems to be a small disadvantage.  I wouldn't go less than 3-4 even if it was no land.  Most times if I get 1 one land good hand I take the risk because I have faith in my deck.
"They were civilized they even drank their blood from a cup"→James Silke/Frank Frazzeta
"When the Cryptkeeper sticks 'em they tend to stay stuck"→Cryptkeeper
"Do not blame the current developers if there is something you don't like about Magic Online. Chances are no one asked the developers for their opinion."→elf
"They just look at me like I'm stupid and then I just say something like well you know WOTC does some dumb things sometimes."→wilmheath
"Like just about everything I've experienced with MTGO and the Magic WotC website, I'm finding it difficult to..."→0rbit
"the more general question is: at what point does an easily fixable interface issue become a defect?"→silentbobus
"Imagine, only four years later and I almost have as much functionality as I used to."→Algona
"WotC, you make an awesome game, why do you have to suck so bad at letting people have a fun time?"→MTGKaioshin
"If you are all about playing as many games as possible as fast as possible and you KNOW you have me beat, then concede and move on"→Johnh2005
"Wow. You're a real pleasure to help.  Good luck figuring it out by yourself."→tempesteye
"2hg brokest of the broke"→Me, Myself & I
"It's you against the shuffler."→jwark
"this look like freeware that some kid down the street crafted up"→ProtossX
"ask them if the world came to an economic end tomorrow, whether they think little printed pieces of paper could be traded for actual goods or services"→dangerlinto
Server status→ http://www.wizards.com/magic/magiconlineserverstatus.asp

Love or hate me I was brought to you courtesy of V3!
Quick Reply
Cancel
Page 11 of 14  •  Prev 1 ... 9 10 11 12 13 14 Next
Jump Menu:
 
    Viewing this thread :: 0 registered and 1 guest
    No registered users viewing