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Longest run (nibble)

Fit to analytical expectation

Expected distribution assumes MD5 acts like a random function. The longest run of matching nibbles is the longest run of successes in 32 iid Bernoulli(1/16) trials.

Expected (now) scales that analytical distribution to the hashes computed so far; Expected (end) scales it to the full 2128 keyspace. Residual is the Pearson residual (Observed − Expected) / √Expected in units of σ. A p-value near 1 means the observed distribution is consistent with random; near 0 means it is statistically surprising.

Distribution moments

Observed Expected
Mean 0.989 0.989
Std. deviation 0.508 0.508

Pearson χ² test

Samples 13,403,995,930,361,856
Reduced χ² 1.036
Degrees of freedom 13
p-value 0.412

Per-bucket detail

Bucket Observed Expected (now) Expected (end) Residual
0 1,699,476,347,990,118 1,699,476,376,612,832 43,143,988,327,398,921,283,734,558,388,424,540,160 −0.69σ
1 10,250,962,782,018,704 10,250,962,693,889,410 260,237,459,546,942,687,931,752,451,700,818,968,576 +0.87σ
2 1,361,561,695,106,224 1,361,561,754,539,226 34,565,472,785,183,526,693,054,308,602,806,796,288 −1.61σ
3 86,422,527,224,805 86,422,524,197,674 2,193,977,172,333,603,584,333,072,206,416,314,368 +0.33σ
4 5,236,226,737,814 5,236,229,934,087 132,930,263,853,445,653,755,221,868,470,599,680 −1.40σ
5 316,078,298,077 316,078,084,418 8,024,159,307,146,040,819,035,019,268,849,664 +0.38σ
6 19,052,761,088 19,052,847,588 483,687,708,315,804,001,578,566,895,534,080 −0.63σ
7 1,146,879,082 1,146,916,389 29,116,349,011,495,305,633,480,149,303,296 −1.10σ
8 68,946,185 68,939,332 1,750,137,728,324,159,119,578,837,811,200 +0.83σ
9 4,135,297 4,137,274 105,031,475,201,429,518,770,711,298,048 −0.97σ
10 248,671 247,865 6,292,458,891,074,704,389,254,938,624 +1.62σ
11 14,818 14,822 376,278,161,354,999,660,715,966,464 −0.03σ
12 920 885 22,454,852,626,045,025,552,171,008 +1.19σ
13 48 53 1,337,020,010,462,468,032,692,224 −0.64σ
14 5 3 79,413,233,237,319,619,706,880 +1.06σ
15 0 0 4,703,919,738,795,935,662,080 −0.43σ
16 0 0 277,782,025,016,212,193,280 −0.10σ
17 0 0 16,348,066,647,354,900,480 −0.03σ
18 0 0 958,422,295,699,783,680 −0.01σ
19 0 0 55,943,151,621,242,880 −0.00σ
20 0 0 3,249,056,860,078,080 −0.00σ
21 0 0 187,604,171,489,280 −0.00σ
22 0 0 10,758,893,076,480 −0.00σ
23 0 0 612,032,839,680 −0.00σ
24 0 0 34,477,178,880 −0.00σ
25 0 0 1,918,894,080 −0.00σ
26 0 0 105,185,280 −0.00σ
27 0 0 5,652,480 −0.00σ
28 0 0 295,680 −0.00σ
29 0 0 14,880 −0.00σ
30 0 0 705 −0.00σ
31 0 0 30 −0.00σ
32 0 0 1 −0.00σ