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Dottir takes November TAZD.
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skrumgaer wrote
at 9:57 AM, Thursday December 1, 2011 EST
The TAZD and baseball-style standings are explained on my Wall. At least 35 regular games played in the month are require to qualify for the monthly TAZD. Shown are Games Behind, TAZD, and player name.
GB TAZD Player 06 12178 dottir 13 11141 Emre Oguz 03 10171 masticore 00 9719 Invola 39 9539 Shevar 03 8878 OneShot7 18 8842 jona_vicente 06 8419 savif 22 8352 [Ocean]Flushed 32 8336 Mazaman 02 8224 toms 10 8170 what_up23 47 8155 jfdis 08 8113 @ata 24 8064 Az_Balu 17 7666 kostur 20 7604 L3xy 48 7603 bcmatteagles 16 7600 22-Apr 11 7427 Lady Lite 07 7406 Vollhonk 66 7294 Scabbard 26 7159 kdiceplaya! 22 6840 chaiNblade 29 6829 IFIGENIUS 17 6518 FPP 24 6504 _smile_ 69 6474 Remiel 43 6441 Simmo3k 40 6411 Mercantile 12 6397 xjxaxnx 11 6328 @Toomyfriends 93 6315 franklyghost 14 6259 Bu7Ch3r 34 6214 fish28 18 6129 Free Flags 19 6043 hcdug 24 5928 kudoukun 18 5921 ovbogaert 14 5907 peter luftig 36 5658 @engr2002 49 5588 EddyB 22 5474 @MikeTamburini 31 5398 Brighty 30 5333 fearlessflyer 39 5281 Lord Death 92 5210 Loobee 35 5123 Gurgi 66 5087 barmat 21 5065 joero14 66 5054 Jily 40 5044 hatty 33 4952 longpube 32 4921 NikkeKnatterton 29 4841 scarp8 54 4794 stackshotbilly 34 4784 OviloN 66 4733 Silesia 100 4730 axlehammer 45 4623 mrb2097 47 4600 nexon 21 4582 Volvic 23 4484 beatol 33 4471 Fatman_x 25 4411 KDancer 41 4306 xXxJozefxXx 25 4289 Keeley 26 4019 euphrates7 87 4003 Rsquared 36 3917 Poker Style 48 3808 "MC" 34 3760 haloducks 41 3641 bivo 69 3261 orestis85 52 3201 greekboi 73 3179 cool g 33 2960 MNK10 57 2817 Trkz 58 2784 greenman 65 2759 These tards suck 76 2714 GreGGwar 70 2500 absolutgimlet 61 2463 Johnboat 44 2285 Kingofskillz 84 2218 DonnieScribbles 93 2208 GR3ENMAN 73 2028 CCSKAOT 94 1253 Kdot 92 1248 ji-jo |
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superxchloe wrote
at 2:20 PM, Sunday December 4, 2011 EST Okay here we go. This is gonna be fun, isn't it? I started this last night, so consider it a direct response to your post from 11:49pm:
"If you use the distribution of percentages rather than the distribution of incidences, there is no multiplier, but to compare distributions of different sample sizes (number of games) you have to *multiply* them by their standard deviations. This is all explained on my Wall." Right. On your three year old wall of technobabble which I have trouble following as a math major. Lemme take a look at that. "The Test Against Pure Luck (TAPL) is a measure of skill that eliminates the random fluctuations that are characteristic of the game-by-game scoring system and rewards players who play more games. " We've all agreed at this point that it's a measure of deviation by its pure nature. "In math jargon, the TAPL is a Pearson?s chi-square goodness of fit test against a uniform distribution." No it isn't. You don't actually run the test. You just find the chi-square statistic. Not quite the same. "The TAPL is the normalized sum of seven numbers. The first number is found by taking the difference between the expected number of first-place finishes and the actual number of first-place finishes, given the number of games played, squaring this difference and dividing it by the expected number of first place finishes. The second number is obtained by doing the same calculation for the second-place finishes. The third number is for the third-place finishes, and so on for all seven levels of finishes. The sum is then divided by the square root of the number of games played to get a result expressed in standard deviations." A chi-square gof is simpler than that- there's no division or multiplication by standard deviation. It's just sum(((observed-expected)^2)/expected). that's it. that's all there is. "The mean of the chi square goes as the number of games played, and its variance goes as the number of games played" mean goes by k and variance goes by 2k, where k is the number of degrees of freedom- which is NOT determined by number of games played. It's 6. Number of categories minus one. So if you decide to convert the percentages to expected COUNTS instead, your formula would be something like this: http://i.imgur.com/mJyGe.png ... I think that's a good stopping place for now. There'll be more later, kids, don't you worry. |
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jurgen wrote
at 3:12 PM, Sunday December 4, 2011 EST great! I was about to play a game after reading this but I will have to wait ten minutes. Reading your post short circuited my mind.
jk, I understand the most part of it and well done |
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greekboi wrote
at 3:36 PM, Sunday December 4, 2011 EST oh man, so much animosity! verm-chloe really hates skrum, and vice versa
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skrumgaer wrote
at 4:50 PM, Sunday December 4, 2011 EST It is the central limit theorem that says that as the number of samples increases, the Pearson's chi square goes to a normal distribution whose mean goes as the number of samples and whose variance goes as the number of samples.
The TAZD is not testing whether a player's distribution is significantly different than the null hypothesis; it is a way of comparing players with different numbers of games. So that is why the totals have to be scaled by the square root of the number of games. To recapture the actual chi-square statistic of a player, divide the player's TAZD by 1000 and multiply by the square root of the number of games. Dottir, for example, has a TAZD of 25137 and has played 6652 games. Her chi-square statistic is 2050.16. For six degrees of freedom, the chi-square test is 12.59 for p = 0.05, 16.81 for p = .01, and 22.40 for p = .001. So Dottir's profile rejects the null hypothesis. If she had had the same profile but with only 66 games, her chi-square would be 204.2 which would still be significant. For a reasonable minimum number of games, we don't have to worry about whether an individual player's profile is statistically significant. |
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superxchloe wrote
at 6:07 PM, Sunday December 4, 2011 EST "The TAZD is not testing whether a player's distribution is significantly different than the null hypothesis"
-> the TAZD isn't a Pearson's chi square goodness of fit test. Which is in fact precisely what I said. The same size isn't about significance- that's not even being brought into question here. Central limit theorem states that as k approaches infinity for a chi-square distribution, the distribution of (X-k)/sqrt(2k) tends toward the normal. where k is DEGREES OF FREEDOM which is NOT determined by sample size for a pearson's chi square. |
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skrumgaer wrote
at 6:33 PM, Sunday December 4, 2011 EST The central limit theorem says that as the number of **samples** from a distribution increases, the mean of the samples approaches a normal distribution even if the original distribution is not normal. Look at the third line in the first paragraph under the heading Classical CLT from this site:
http://en.wikipedia.org/wiki/Central_limit_theorem and observe the variance of the mean in the expression. |
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superxchloe wrote
at 6:44 PM, Sunday December 4, 2011 EST |
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skrumgaer wrote
at 7:01 PM, Sunday December 4, 2011 EST In that article, k is the number of observations, not the number of cells. In some of the other Wikipedia articles, the number of observations is referred to as n. So, for a large number of observations, the central limit theorem kicks in, as it is supposed to.
Nice try, though. |
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superxchloe wrote
at 7:12 PM, Sunday December 4, 2011 EST In that article k is degrees of freedom.
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skrumgaer wrote
at 7:20 PM, Sunday December 4, 2011 EST which is not relevant here because we both agree that the Pearson's chi square used in the TAZD has six degrees of freedom.
We both should agree that the number of observations is equal to the number of games, and what triggers the central limit thorem is the number of observations. So the central limit theorem holds, and you have to deal with it. |