if the above is incorrect please show how and please show you math.
The first problem with your statistics is you are just using shares in your calculations. This is not how you would calculate the expected round length. When mining Bitcoins, round length percentiles (the chances a round will go as long as it did) are a binomial distribution based on the number of total
independent hashes. What you are doing is equivalent to taking interest compounded monthly, using stats about the interest where it is compounded yearly, and trying to fit it to a curve that would be for interest compounded continuously. Actually, it looks like you are just adding up the total number of shares, instead of fitting them to a round quantile, which is even farther from what you should be doing.
Here is an example of how percentile calculations using just the number of shares and ignoring the underlying difficulty 1 binomial distribution of share finding will skew your results. This is using real binomial percentile calculation instead of whatever you are doing...
This is a table of all block finds for the last difficulty at BTCg.
# Block Date/Time Duration Shares Total Hashes percentile share percentile
2362 141124 08/16/11 12:11 AM 04:56:00 7609114 02.656% 01.479%
2363 141125 08/16/11 12:37 AM 00:26:00 0681963 72.239% 68.546%
2364 141130 08/16/11 01:29 AM 00:52:00 1350501 52.520% 47.335%
2365 141135 08/16/11 02:25 AM 00:56:25 1484443 49.271% 43.951%
2366 141136 08/16/11 02:31 AM 00:05:30 0143481 93.387% 92.361%
2367 141147 08/16/11 05:31 AM 03:00:05 4832611 09.982% 06.882%
2368 141153 08/16/11 06:09 AM 00:38:01 1054539 60.481% 55.766%
2369 141160 08/16/11 07:12 AM 01:03:00 1735924 43.703% 38.237%
2370 141162 08/16/11 07:36 AM 00:24:31 0698169 71.683% 67.933%
2371 141165 08/16/11 07:56 AM 00:19:28 0529012 77.705% 74.605%
2372 141168 08/16/11 08:44 AM 00:48:00 1358208 52.328% 47.134%
2373 141170 08/16/11 09:07 AM 00:23:14 0667927 72.724% 69.080%
2374 141173 08/16/11 10:16 AM 01:08:56 1926729 39.902% 34.403%
2375 141179 08/16/11 11:05 AM 00:49:23 1385716 51.646% 46.421%
2376 141182 08/16/11 11:41 AM 00:35:28 0972989 62.879% 58.342%
2377 141183 08/16/11 11:46 AM 00:04:59 0135719 93.733% 92.759%
2378 141188 08/16/11 12:21 PM 00:35:54 1012043 61.719% 57.094%
2379 141198 08/16/11 01:41 PM 01:19:07 2209830 34.864% 29.411%
2380 141203 08/16/11 02:05 PM 00:23:59 0667575 72.737% 69.094%
2381 141209 08/16/11 02:38 PM 00:33:11 0942983 63.785% 59.320%
2382 141211 08/16/11 02:45 PM 00:06:49 0183003 91.644% 90.362%
2383 141215 08/16/11 03:10 PM 00:25:02 0700124 71.616% 67.860%
2384 141218 08/16/11 03:32 PM 00:21:58 0607330 74.856% 71.438%
2385 141220 08/16/11 03:53 PM 00:21:39 0616836 74.518% 71.063%
2386 141223 08/16/11 04:19 PM 00:25:21 0696526 71.739% 67.995%
2387 141230 08/16/11 05:49 PM 01:30:01 2501908 30.331% 25.018%
2388 141242 08/16/11 08:00 PM 02:11:00 3533660 18.545% 14.129%
2389 141245 08/16/11 08:21 PM 00:21:25 0578235 75.902% 72.598%
2390 141247 08/16/11 08:48 PM 00:27:14 0677616 72.389% 68.711%
2391 141252 08/16/11 09:42 PM 00:53:20 1266941 54.655% 49.577%
2392 141256 08/16/11 10:06 PM 00:24:05 0575149 76.014% 72.723%
2393 141266 08/16/11 11:48 PM 01:42:11 2462278 30.910% 25.573%
2394 141274 08/17/11 12:38 AM 00:49:44 1166794 57.329% 52.405%
2395 141277 08/17/11 01:25 AM 00:47:00 0946058 63.692% 59.219%
2396 141278 08/17/11 01:32 AM 00:07:01 0105215 95.107% 94.340%
2397 141279 08/17/11 01:42 AM 00:10:00 0206608 90.618% 89.188%
2398 141283 08/17/11 02:30 AM 00:47:59 1016167 61.598% 56.964%
2399 141295 08/17/11 04:55 AM 02:25:01 3412584 19.647% 15.109%
2400 141306 08/17/11 07:21 AM 02:26:52 3623270 17.769% 13.445%
2401 141308 08/17/11 07:29 AM 00:07:08 0173062 92.079% 90.861%
2402 141310 08/17/11 07:39 AM 00:10:30 0258664 88.396% 86.654%
2403 141326 08/17/11 11:04 AM 03:24:44 5139667 08.623% 05.806%
2404 141331 08/17/11 12:00 PM 00:56:01 1413260 50.972% 45.719%
2405 141333 08/17/11 12:52 PM 00:52:33 1350274 52.526% 47.341%
2406 141341 08/17/11 02:27 PM 01:34:12 2381984 32.116% 26.736%
2407 141342 08/17/11 02:33 PM 00:06:00 0145661 93.290% 92.250%
2408 141358 08/17/11 06:12 PM 03:39:04 5684853 06.649% 04.293%
2409 141380 08/17/11 09:04 PM 02:52:42 4480611 11.806% 08.363%
2410 141382 08/17/11 09:11 PM 00:07:00 0170823 92.177% 90.973%
2411 141384 08/17/11 09:40 PM 00:29:01 0756007 69.733% 65.792%
2412 141389 08/17/11 10:11 PM 00:30:46 0794891 68.452% 64.390%
2413 141392 08/17/11 10:39 PM 00:28:07 0727708 70.681% 66.831%
2414 141401 08/17/11 11:41 PM 01:01:20 1562514 47.470% 42.092%
2415 141411 08/18/11 01:18 AM 01:37:00 2482370 30.615% 25.291%
2416 141419 08/18/11 02:21 AM 01:02:55 1661534 45.281% 39.846%
2417 141430 08/18/11 03:28 AM 01:07:04 1768458 43.030% 37.555%
2418 141431 08/18/11 03:31 AM 00:03:01 0074000 96.533% 95.985%
2419 141445 08/18/11 03:31 AM 00:00:02 0001780 99.915% 99.901%
2420 141478 08/18/11 05:53 AM 02:21:57 3883147 15.698% 11.643%
2421 141450 08/18/11 06:53 AM 01:00:01 1699965 44.459% 39.006%
2422 141432 08/18/11 08:13 AM 01:19:59 2297726 33.433% 28.013%
2423 141457 08/18/11 09:15 AM 01:02:00 1725020 43.931% 38.469%
2424 141461 08/18/11 10:54 AM 01:39:51 2664088 28.074% 22.869%
2425 141470 08/18/11 12:08 PM 01:13:10 2005153 38.438% 32.941%
2426 141487 08/18/11 01:34 PM 01:25:59 2386828 32.042% 26.665%
2427 141496 08/18/11 03:20 PM 01:46:43 2997992 23.942% 19.008%
2428 141501 08/18/11 04:00 PM 00:39:40 1124282 58.503% 53.653%
2429 141510 08/18/11 05:30 PM 01:29:38 2507835 30.245% 24.936%
2430 141512 08/18/11 05:38 PM 00:08:01 0226044 89.782% 88.233%
2431 141514 08/18/11 05:47 PM 00:08:58 0257777 88.434% 86.696%
2432 141526 08/18/11 07:39 PM 01:52:10 3112459 22.670% 17.841%
2433 141532 08/18/11 08:20 PM 00:40:50 1120369 58.612% 53.770%
2434 141545 08/18/11 10:46 PM 02:26:13 3924076 15.395% 11.382%
2435 141546 08/18/11 11:28 PM 00:42:22 1175575 57.089% 52.151%
2436 141552 08/19/11 01:02 AM 01:33:25 2600589 28.937% 23.688%
2437 141558 08/19/11 01:45 AM 00:43:00 1188897 56.728% 51.767%
2438 141566 08/19/11 03:03 AM 01:18:12 2131499 36.190% 30.715%
2439 141569 08/19/11 03:32 AM 00:28:48 0775002 69.105% 65.103%
2440 141573 08/19/11 04:10 AM 00:38:01 1043501 60.800% 56.108%
2441 141574 08/19/11 04:26 AM 00:16:34 0467272 80.026% 77.200%
2442 141575 08/19/11 04:42 AM 00:15:25 0415757 82.017% 79.434%
2443 141586 08/19/11 06:27 AM 01:45:01 2984100 24.101% 19.155%
2444 141600 08/19/11 09:12 AM 02:45:39 4779202 10.240% 07.088%
2445 141605 08/19/11 09:39 AM 00:26:20 0753706 69.810% 65.875%
2446 141615 08/19/11 11:44 AM 02:05:04 3631839 17.697% 13.381%
2447 141616 08/19/11 12:00 PM 00:15:53 0482024 79.466% 76.571%
2448 141618 08/19/11 12:25 PM 00:25:03 0733702 70.479% 66.609%
2449 141619 08/19/11 12:32 PM 00:07:01 0205693 90.657% 89.234%
2450 141622 08/19/11 01:18 PM 00:46:11 1371842 51.989% 46.779%
2451 141628 08/19/11 01:46 PM 00:27:48 0797782 68.358% 64.287%
2452 141631 08/19/11 02:47 PM 01:01:00 1799350 42.401% 36.918%
2453 141644 08/19/11 04:51 PM 02:04:24 3688955 17.221% 12.965%
2454 141671 08/19/11 10:38 PM 05:46:41 9937498 00.875% 00.407%
2455 141673 08/19/11 10:53 PM 00:14:52 0430853 81.428% 78.772%
2456 141674 08/19/11 11:03 PM 00:10:28 0299371 86.697% 84.722%
2457 141695 08/20/11 02:28 AM 03:25:21 5818787 06.237% 03.986%
2458 141701 08/20/11 03:17 AM 00:48:15 1391035 51.515% 46.285%
2459 141703 08/20/11 03:54 AM 00:36:59 1074718 59.902% 55.146%
2460 141709 08/20/11 04:29 AM 00:35:01 1003017 61.985% 57.380%
2461 141711 08/20/11 04:44 AM 00:15:10 0449461 80.709% 77.965%
2462 Invalid 08/20/11 06:38 AM 01:53:50 3305441 20.677% 16.032%
2463 141733 08/20/11 08:25 AM 01:47:02 3212302 21.616% 16.881%
2464 141734 08/20/11 08:31 AM 00:06:34 0189122 91.377% 90.056%
2465 141747 08/20/11 10:14 AM 01:42:29 3054329 23.307% 18.424%
2466 141756 08/20/11 11:44 AM 01:30:44 2728916 27.219% 22.063%
2467 141759 08/20/11 11:50 AM 00:05:29 0157588 92.761% 91.643%
2468 141760 08/20/11 12:18 PM 00:27:47 0835741 67.132% 62.950%
2469 141780 08/20/11 02:20 PM 02:02:25 3677391 17.316% 13.048%
2470 141782 08/20/11 03:47 PM 01:26:34 2558765 29.520% 24.243%
2471 141784 08/20/11 03:56 PM 00:09:00 0274134 87.747% 85.915%
2472 141767 08/20/11 04:08 PM 00:12:00 0360555 84.204% 81.900%
2473 141781 08/20/11 04:10 PM 00:02:01 0039201 98.148% 97.852%
2474 141802 08/20/11 07:51 PM 03:41:47 6420919 04.681% 02.856%
2475 141810 08/20/11 09:23 PM 01:31:16 2588165 29.109% 23.851%
2476 141815 08/20/11 09:37 PM 00:13:56 0380546 83.405% 80.998%
2477 141818 08/20/11 09:48 PM 00:11:01 0308384 86.325% 84.300%
2478 141821 08/20/11 10:35 PM 00:47:01 1333068 52.959% 47.795%
2479 141828 08/20/11 11:29 PM 00:53:58 1546878 47.826% 42.458%
2480 141834 08/21/11 12:26 AM 00:57:00 1621428 46.155% 40.740%
2481 141836 08/21/11 12:53 AM 00:27:07 0782568 68.856% 64.831%
2482 141854 08/21/11 04:32 AM 03:38:53 6243885 05.093% 03.150%
2483 141855 08/21/11 04:46 AM 00:14:44 0444035 80.918% 78.199%
2484 141864 08/21/11 06:13 AM 01:26:55 2516246 30.124% 24.820%
2485 141869 08/21/11 06:34 AM 00:20:26 0580633 75.816% 72.502%
2486 141870 08/21/11 06:49 AM 00:14:45 0451507 80.630% 77.877%
2487 141874 08/21/11 07:36 AM 00:47:36 1400203 51.290% 46.050%
2488 141877 08/21/11 07:57 AM 00:21:03 0616930 74.515% 71.059%
2489 141894 08/21/11 10:35 AM 02:37:31 4647383 10.904% 07.625%
2490 141896 08/21/11 10:38 AM 00:02:51 0088585 95.864% 95.213%
2491 141901 08/21/11 11:24 AM 00:46:10 1363241 52.202% 47.003%
2492 141903 08/21/11 12:24 PM 00:59:59 1674707 44.998% 39.556%
2493 141911 08/21/11 01:23 PM 00:59:00 1711755 44.210% 38.753%
2494 141915 08/21/11 01:39 PM 00:16:00 0474834 79.738% 76.877%
2495 141914 08/21/11 01:40 PM 00:00:50 0021798 98.966% 98.800%
2496 141916 08/21/11 01:48 PM 00:08:10 0232932 89.488% 87.898%
2497 141923 08/21/11 03:09 PM 01:21:01 2249399 34.212% 28.773%
2498 141924 08/21/11 03:10 PM 00:01:00 0031841 98.493% 98.252%
2499 141935 08/21/11 05:03 PM 01:53:06 3301770 20.713% 16.065%
2500 141951 08/21/11 07:14 PM 02:11:24 3699692 17.133% 12.888%
2501 141955 08/21/11 07:40 PM 00:25:29 0668345 72.710% 69.064%
2502 141968 08/21/11 09:38 PM 01:58:07 3137588 22.400% 17.594%
2503 141980 08/21/11 11:11 PM 01:32:54 2377221 32.189% 26.807%
2504 141990 08/21/11 11:57 PM 00:46:09 1176870 57.054% 52.113%
2505 141991 08/21/11 11:59 PM 00:01:50 0045022 97.876% 97.538%
2506 141993 08/22/11 12:07 AM 00:08:01 0205596 90.662% 89.238%
2507 142001 08/22/11 12:54 AM 00:47:44 1245173 55.226% 50.179%
2508 142003 08/22/11 01:02 AM 00:07:15 0174270 92.026% 90.800%
2509 142004 08/22/11 01:07 AM 00:05:00 0136568 93.695% 92.716%
2510 142005 08/22/11 01:21 AM 00:14:39 0388225 83.100% 80.654%
2511 142011 08/22/11 02:12 AM 00:50:22 1298670 53.835% 48.714%
2512 142015 08/22/11 02:42 AM 00:30:38 0813555 67.846% 63.728%
2513 142016 08/22/11 02:45 AM 00:02:21 0049561 97.664% 97.293%
2514 142025 08/22/11 04:23 AM 01:38:01 2551980 29.615% 24.334%
2515 142033 08/22/11 05:20 AM 00:57:38 1542625 47.923% 42.558%
2516 142055 08/22/11 07:48 AM 02:27:22 4054779 14.465% 10.587%
2517 142059 08/22/11 08:38 AM 00:50:20 1424492 50.700% 45.435%
2518 142061 08/22/11 09:42 AM 01:03:54 1845962 41.469% 35.977%
2519 142064 08/22/11 09:53 AM 00:10:45 0284980 87.294% 85.400%
2520 142065 08/22/11 10:00 AM 00:07:02 0195652 91.093% 89.731%
2521 142088 08/22/11 12:55 PM 02:54:58 4960234 09.393% 06.412%
2522 142099 08/22/11 03:04 PM 02:09:43 3686401 17.242% 12.983%
2523 142116 08/22/11 05:49 PM 02:44:55 4656867 10.855% 07.585%
2524 142118 08/22/11 06:09 PM 00:19:22 0543406 77.173% 74.012%
2525 142121 08/22/11 06:31 PM 00:22:36 0635583 73.855% 70.329%
2526 142129 08/22/11 08:03 PM 01:31:24 2545096 29.713% 24.427%
2527 142140 08/22/11 09:28 PM 01:25:00 2364648 32.383% 26.994%
2528 142141 08/22/11 09:36 PM 00:08:04 0233339 89.470% 87.878%
2529 142143 08/22/11 09:50 PM 00:14:00 0375147 83.620% 81.240%
2530 142146 08/22/11 10:00 PM 00:09:56 0271610 87.852% 86.035%
2531 142168 08/23/11 12:57 AM 02:57:12 4958392 09.401% 06.419%
2532 142173 08/23/11 01:58 AM 01:01:36 1762323 43.156% 37.682%
2533 142174 08/23/11 02:06 AM 00:07:03 0200533 90.881% 89.489%
2534 142184 08/23/11 02:48 AM 00:42:09 1185587 56.817% 51.862%
2535 142194 08/23/11 04:43 AM 01:54:50 3324331 20.491% 15.866%
2536 142195 08/23/11 04:50 AM 00:07:26 0216254 90.202% 88.713%
2537 142202 08/23/11 05:56 AM 01:05:37 1913737 40.150% 34.651%
2538 142211 08/23/11 07:16 AM 01:20:48 2284651 33.642% 28.217%
2539 142213 08/23/11 07:42 AM 00:25:52 0753785 69.807% 65.873%
2540 142221 08/23/11 08:30 AM 00:47:27 1348127 52.580% 47.398%
2541 142230 08/23/11 09:33 AM 01:03:01 1811406 42.158% 36.672%
2542 142231 08/23/11 09:39 AM 00:06:00 0170895 92.174% 90.970%
2543 142244 08/23/11 10:59 AM 01:20:00 2283738 33.656% 28.231%
2544 142251 08/23/11 12:14 PM 01:15:21 2200739 35.015% 29.559%
2545 142258 08/23/11 01:06 PM 00:51:53 1510217 48.669% 43.328%
2546 142278 08/23/11 03:21 PM 02:15:12 3917862 15.440% 11.421%
2547 142300 08/23/11 08:49 PM 05:28:01 6801826 03.903% 02.312%
2548 142301 08/23/11 08:56 PM 00:06:28 1028646 61.232% 56.571%
2549 142303 08/23/11 09:30 PM 00:34:01 2438248 31.266% 25.916%
2550 142322 08/24/11 12:33 AM 03:03:04 5186095 08.434% 05.658%
2551 142328 08/24/11 02:03 AM 01:29:59 2511933 30.186% 24.880%
2552 142333 08/24/11 02:45 AM 00:42:00 1156510 57.610% 52.704%
2553 142346 08/24/11 05:23 AM 02:38:00 4420084 12.152% 08.648%
2554 142349 08/24/11 05:36 AM 00:13:00 0358914 84.270% 81.974%
2555 142358 08/24/11 07:08 AM 01:32:15 2660622 28.120% 22.913%
2556 142363 08/24/11 07:34 AM 00:26:28 0756036 69.732% 65.791%
2557 142365 08/24/11 07:42 AM 00:08:01 0228131 89.693% 88.132%
2558 142368 08/24/11 07:58 AM 00:15:09 0435106 81.263% 78.587%
2559 142376 08/24/11 09:49 AM 01:50:58 3195791 21.787% 17.036%
2560 142391 08/24/11 11:35 AM 01:46:10 3025469 23.630% 18.721%
2561 142408 08/24/11 02:58 PM 03:22:58 5791868 06.318% 04.046%
2562 142421 08/24/11 06:26 PM 03:28:18 5851416 06.141% 03.914%
2563 142425 08/24/11 08:07 PM 01:40:54 2775808 26.617% 21.497%
2564 142427 08/24/11 08:23 PM 00:15:49 0418619 81.905% 79.308%
2565 142439 08/24/11 09:51 PM 01:28:24 2402909 31.797% 26.428%
2566 142445 08/24/11 11:27 PM 01:35:36 2540231 29.782% 24.493%
2567 142456 08/25/11 01:05 AM 01:38:00 2559087 29.515% 24.239%
2568 142466 08/25/11 02:26 AM 01:21:04 2116696 36.447% 30.968%
2569 142472 08/25/11 04:17 AM 01:50:57 2931173 24.717% 19.725%
2570 142478 08/25/11 04:43 AM 00:26:17 0715194 71.104% 67.296%
2571 142485 08/25/11 05:35 AM 00:51:42 1379627 51.796% 46.578%
2572 142489 08/25/11 06:23 AM 00:48:00 1294650 53.938% 48.822%
2573 142495 08/25/11 07:31 AM 01:08:00 1824487 41.896% 36.407%
2574 142501 08/25/11 08:36 AM 01:05:47 1772265 42.952% 37.475%
2575 142503 08/25/11 08:45 AM 00:08:13 0202233 90.807% 89.405%
2576 142504 08/25/11 08:51 AM 00:06:39 0188678 91.396% 90.078%
2577 142509 08/25/11 09:33 AM 00:41:31 1112043 58.845% 54.018%
2578 142520 08/25/11 11:11 AM 01:37:50 2622165 28.641% 23.406%
2579 142525 08/25/11 12:29 PM 01:18:22 2152234 35.834% 30.364%
2580 142536 08/25/11 03:07 PM 02:37:40 4291742 12.919% 09.285%
2581 142542 08/25/11 05:03 PM 01:56:19 3162430 22.136% 17.354%
2582 142549 08/25/11 06:35 PM 01:31:39 2456122 31.000% 25.661%
2583 142563 08/25/11 09:01 PM 02:26:00 3838146 16.039% 11.936%
2584 142564 08/25/11 09:03 PM 00:02:01 0054250 97.446% 97.040%
2585 142572 08/25/11 10:09 PM 01:05:59 1697227 44.517% 39.066%
2586 142580 08/25/11 11:05 PM 00:56:20 1440643 50.311% 45.030%
2587 142579 08/25/11 11:05 PM 00:00:17 0005253 99.750% 99.710%
2588 142585 08/26/11 12:03 AM 00:57:23 1457687 49.903% 44.607%
2589 142589 08/26/11 12:24 AM 00:21:14 0549533 76.948% 73.762%
2590 142591 08/26/11 12:50 AM 00:25:46 0657659 73.081% 69.474%
2591 142601 08/26/11 01:40 AM 00:50:00 1268784 54.607% 49.527%
2592 142614 08/26/11 03:08 AM 01:28:01 2284627 33.642% 28.217%
2593 142625 08/26/11 05:27 AM 02:18:59 3666314 17.408% 13.128%
2594 142677 08/26/11 05:27 AM 00:00:03 0000663 99.968% 99.963%
2595 142641 08/26/11 06:20 AM 00:52:58 1410142 51.048% 45.798%
2596 142626 08/26/11 07:08 AM 00:47:59 1265316 54.698% 49.622%
2597 142632 08/26/11 01:53 PM 06:45:37 10648774 00.623% 00.275%
2598 142685 08/26/11 04:05 PM 02:11:23 3311627 20.616% 15.978%
2599 142690 08/26/11 04:40 PM 00:35:00 0856172 66.481% 62.241%
2600 142699 08/26/11 06:03 PM 01:22:50 2045320 37.709% 32.216%
2601 142698 08/26/11 06:16 PM 00:13:09 0224481 89.849% 88.310%
2602 142700 08/26/11 06:35 PM 00:19:20 0559432 76.586% 73.358%
2603 142712 08/26/11 08:05 PM 01:30:30 2196947 35.078% 29.621%
2604 142715 08/26/11 08:43 PM 00:37:57 0925473 64.320% 59.898%
2605 142731 08/26/11 11:33 PM 02:49:44 4061634 14.417% 10.547%
2606 142737 08/27/11 12:46 AM 01:12:30 1704244 44.368% 38.914%
2607 142740 08/27/11 01:40 AM 00:54:01 1269611 54.586% 49.504%
2608 142747 08/27/11 04:00 AM 02:19:59 3332412 20.413% 15.795%
2609 142748 08/27/11 04:20 AM 00:19:57 0475795 79.702% 76.836%
2610 142759 08/27/11 05:08 AM 00:48:08 1141242 58.031% 53.152%
2611 142760 08/27/11 05:30 AM 00:22:14 0545689 77.089% 73.919%
2612 142767 08/27/11 06:31 AM 01:00:36 1461931 49.803% 44.503%
2613 142775 08/27/11 08:50 AM 02:19:05 3378500 19.969% 15.397%
2614 142793 08/27/11 11:52 AM 03:02:00 4441617 12.028% 08.545%
2615 142801 08/27/11 01:28 PM 01:36:01 2381076 32.130% 26.750%
2616 142811 08/27/11 03:21 PM 01:52:56 2817633 26.092% 21.005%
2617 142824 08/27/11 04:36 PM 01:15:04 1852772 41.335% 35.841%
2618 142825 08/27/11 04:59 PM 00:22:59 0586722 75.596% 72.258%
2619 142837 08/27/11 07:55 PM 02:56:00 4293643 12.907% 09.275%
2620 142840 08/27/11 08:07 PM 00:12:18 0293147 86.955% 85.015%
2621 142842 08/27/11 08:34 PM 00:26:50 0642278 73.619% 70.069%
2622 142847 08/27/11 10:18 PM 01:43:48 2473242 30.748% 25.419%
2623 142850 08/27/11 11:20 PM 01:02:07 1454249 49.985% 44.692%
2624 142852 08/27/11 11:30 PM 00:10:02 0241919 89.105% 87.461%
2625 142854 08/28/11 12:02 AM 00:32:22 0759580 69.615% 65.662%
2626 142862 08/28/11 02:38 AM 02:35:48 3650511 17.540% 13.244%
2627 142863 08/28/11 02:46 AM 00:07:56 0183507 91.622% 90.337%
2628 142865 08/28/11 03:01 AM 00:15:12 0356376 84.372% 82.089%
2629 142866 08/28/11 03:04 AM 00:02:51 0063392 97.022% 96.550%
2630 142897 08/28/11 08:44 AM 05:39:46 8016526 02.187% 01.180%
2631 142907 08/28/11 11:09 AM 02:24:50 3461476 19.194% 14.705%
2632 142913 08/28/11 12:59 PM 01:50:06 2670659 27.986% 22.786%
2633 142917 08/28/11 01:27 PM 00:27:57 0675141 72.475% 68.805%
2634 142921 08/28/11 02:49 PM 01:22:33 1998135 38.567% 33.069%
2635 142934 08/28/11 04:26 PM 01:36:34 2294743 33.480% 28.060%
2636 142954 08/28/11 08:24 PM 03:58:00 5595685 06.937% 04.510%
2637 142957 08/28/11 08:44 PM 00:20:12 0494324 79.001% 76.052%
2638 142964 08/28/11 10:56 PM 02:11:48 3201088 21.732% 16.986%
2639 142967 08/28/11 11:22 PM 00:26:10 0654882 73.178% 69.581%
2640 142972 08/29/11 12:11 AM 00:49:36 1232654 55.556% 50.528%
2641 142974 08/29/11 12:40 AM 00:28:14 0699448 71.640% 67.885%
2642 142984 08/29/11 01:56 AM 01:16:40 1928985 39.859% 34.360%
2643 142990 08/29/11 02:41 AM 00:44:20 1098627 59.223% 54.421%
2644 142993 08/29/11 03:06 AM 00:25:04 0648936 73.386% 69.811%
2645 142994 08/29/11 03:14 AM 00:08:00 0201389 90.844% 89.446%
2646 142996 08/29/11 03:44 AM 00:30:19 0768774 69.310% 65.328%
2647 143002 08/29/11 05:57 AM 02:12:50 3437147 19.418% 14.905%
2648 143016 08/29/11 09:12 AM 03:14:48 5176607 08.472% 05.688%
2649 143028 08/29/11 10:55 AM 01:43:31 2795485 26.369% 21.264%
2650 143043 08/29/11 12:02 PM 01:06:57 1796155 42.466% 36.983%
2651 143048 08/29/11 12:40 PM 00:37:39 1030350 61.182% 56.518%
2652 143052 08/29/11 01:36 PM 00:56:22 1550462 47.744% 42.373%
2653 143062 08/29/11 04:16 PM 02:39:51 4299717 12.870% 09.244%
2654 143074 08/29/11 06:44 PM 02:27:59 3974780 15.027% 11.067%
2655 143087 08/29/11 09:11 PM 02:27:11 3895349 15.607% 11.564%
2656 143091 08/29/11 10:14 PM 01:02:23 1644946 45.641% 40.213%
2657 143092 08/29/11 10:23 PM 00:09:27 0261903 88.260% 86.499%
2658 143093 08/29/11 10:30 PM 00:06:59 0184834 91.564% 90.270%
2659 143110 08/30/11 01:08 AM 02:38:13 4194390 13.533% 09.799%
2660 143111 08/30/11 01:17 AM 00:08:21 0214580 90.274% 88.795%
2661 143114 08/30/11 01:41 AM 00:24:31 0650079 73.346% 69.767%
2662 143115 08/30/11 01:50 AM 00:09:10 0242691 89.072% 87.424%
2663 143120 08/30/11 02:48 AM 00:57:39 1536122 48.072% 42.711%
2664 143127 08/30/11 03:58 AM 01:10:14 1872587 40.946% 35.450%
Mean percentile using estimated total hashes: 52.41%
Mean percentile using shares vs difficulty: 48.60%
Mean # of shares:1831414.1320132
(We can see above that accusations of the pool being unlucky are already specious, as the pool found blocks with 101.4% of the expected shares, pretty darn close.)
As you can see, the last two percentile columns do not match. in the first, I have estimated the number of shares per difficulty 1 block solve to get the
total hashes computed at that round's difficulty, and
then determined the percentile for the full probability; in the second I have naively just used the number of shares. You can see that I get different results. This is the problem with just using somebody's CDF calculator without understanding the statistics behind it.
Secondly, you are making some kind of statement that BTC guild has been improbably unlucky. Could we can blame the luck of the miners? Maybe their submitted shares are unlucky? We must first analyze if we can expect the difficulty 1 block solves to correlate to hash rate.
For this I use the R statistics package. The probability of a single hash producing a block solve at difficulty 1 is 2^-32, and I am going to find the 95% confidence interval of probability for a single block find:
R version 2.13.1 (2011-07-08)
Copyright (C) 2011 The R Foundation for Statistical Computing
> dif1prob <- 2^-32
> dif1trials <- 2^32
> oneblock <- 1
> binom.test(x = oneblock, n = dif1trials, p = dif1prob, conf.level = 0.95)
Exact binomial test
data: oneblock and dif1trials
number of successes = 1, number of trials = 4294967296, p-value = 1
alternative hypothesis: true probability of success is not equal to 2.328306e-10
95 percent confidence interval:
5.894762e-12 1.297249e-09
sample estimates:
probability of success
2.328306e-10
Here we can see that if we find a single block at difficulty 1 with the expected average number of hashes, we would have a very wide number of hashes possible for a block solve where we can still say with 95% confidence that the probability is correct. We also know intuitively that a lucky person could find a block in just a few hashes, which would lie outside the confidence interval, showing that even statistics can't absolutely doubt random events. How about if we increase this to 100,000 blocks at the same block solve rate?:
> binom.test(x = oneblock*100000, n = dif1trials*100000, p = dif1prob, conf.level = 0.95)
Exact binomial test
data: oneblock * 1e+05 and dif1trials * 1e+05
number of successes = 1e+05, number of trials = 4.294967e+14, p-value = 1
alternative hypothesis: true probability of success is not equal to 2.328306e-10
95 percent confidence interval:
2.313898e-10 2.342786e-10
sample estimates:
probability of success
2.328306e-10
Here we can see that the confidence interval lies between 2.31 and 2.34 (x 10^-10), a much smaller range, so we can intuit that with over 100,000 shares submitted, with 95% confidence that the luck of share finding shouldn't deviate more than 1% (but in 1 of 20 cases we can predict it will).
So now we look at the blocks of BTC guild and see if we have enough statistics to make any conclusion. Let's pick a rather "unlucky" day, 8/24, where 17 blocks were found with 43715542 shares (an average of 2571502 shares per round, at difficulty 1805700.83). I'm going to compute with just shares first so I don't run out of memory...:
> x<-17
> N<-43715542
> prob<-(1/1805700.83)
> dbinom(x, N, prob)
[1] 0.02901398
Here we get the percentile of 2.9%; these odds can be expected averaging 1 in 34 days.
Can we say though that the game is "fixed", that the probability this day is not what is expected?
> binom.test(x, N, prob)
Exact binomial test
data: x and N
number of successes = 17, number of trials = 43715542, p-value = 0.1547
alternative hypothesis: true probability of success is not equal to 5.538016e-07
95 percent confidence interval:
2.265356e-07 6.226308e-07
sample estimates:
probability of success
3.888777e-07
The "alternative hypothesis" as represented above is what would be outside the confidence level, that the probability is not the Bitcoin probability, maybe luck being affected by the pool op. We can see that both the bitcoin probability and the probability estimate from the results are both within the confidence interval, meaning that these results do not deviate outside an expected block solve rate for the day.
These numbers are now large enough that the discrete binomial distribution has approached the continuous poisson model for the same data (shown below), and we can then do even bigger math:
> poisson.test(x, N, prob)
Exact Poisson test
data: x time base: N
number of events = 17, time base = 43715542, p-value = 0.1547
alternative hypothesis: true event rate is not equal to 5.538016e-07
95 percent confidence interval:
2.265356e-07 6.226309e-07
sample estimates:
event rate
3.888777e-07
Now let's look at the data for the whole two-week difficulty period where 303 blocks were found with 554918482 shares:
> x2w <-303
> N2w <-554918482
> poisson.test(x2w, N2w, prob)
Exact Poisson test
data: x2w time base: N2w
number of events = 303, time base = 554918482, p-value = 0.8417
alternative hypothesis: true event rate is not equal to 5.538016e-07
95 percent confidence interval:
4.862695e-07 6.110991e-07
sample estimates:
event rate
5.460261e-07
Lets do the full expansion based on the total hashrate, and even go a step further and say that the shares being submitted this whole time were 0.5% luckier than expected, resulting in more hashrate trials per submitted share:
> poisson.test(x2w, ((N2w*2^32)*1.005), (prob*2^-32))
Exact Poisson test
data: x2w time base: ((N2w * 2^32) * 1.005)
number of events = 303, time base = 2.395274e+18, p-value = 0.776
alternative hypothesis: true event rate is not equal to 1.28942e-16
95 percent confidence interval:
1.126552e-16 1.415747e-16
sample estimates:
event rate
1.264991e-16
I think you get the idea, the estimated block win rate of BTC Guild is well within the expected confidence range, the Vladimir hypothesis is busted.
Edit: maybe clearer, probably not...