Exhibit

Longest runs.

Look down a shuffled deck for the longest stretch of a single color. Usually it is five or six cards. This room holds the shuffles where it reached fifteen or more.

What is ranked

The longest run of consecutive cards of the same color, red or black, anywhere in the 52-card order. Ties are ordered by archive number, oldest first.

How rare

Of all possible decks, about one in 10,769 contains a run of 15 or more. The exact distribution comes from a dynamic program over every arrangement of 26 red and 26 black cards.

The record

20 red

Shuffle #8,262,620, recorded August 4, 2025. 1,324 shuffles have qualified so far.

RankShuffleRun lengthShuffledEra
501#1,498,70715 redMay 16, 20252025 engine
502#1,500,76615 blackMay 16, 20252025 engine
503#1,507,11215 redMay 16, 20252025 engine
504#1,514,96915 blackMay 17, 20252025 engine
505#1,516,15415 blackMay 17, 20252025 engine
506#1,523,00415 redMay 17, 20252025 engine
507#1,523,77615 blackMay 17, 20252025 engine
508#1,534,46615 blackMay 17, 20252025 engine
509#1,537,84315 blackMay 17, 20252025 engine
510#1,549,01115 blackMay 17, 20252025 engine
511#1,552,56015 redMay 17, 20252025 engine
512#1,555,96015 redMay 17, 20252025 engine
513#1,557,96115 blackMay 17, 20252025 engine
514#1,563,39815 redMay 17, 20252025 engine
515#1,565,76415 blackMay 17, 20252025 engine
516#1,600,58215 redMay 18, 20252025 engine
517#1,622,38515 blackMay 18, 20252025 engine
518#1,622,43615 redMay 18, 20252025 engine
519#1,628,32215 blackMay 18, 20252025 engine
520#1,681,23615 redMay 19, 20252025 engine
521#1,687,57715 redMay 19, 20252025 engine
522#1,713,47915 blackMay 19, 20252025 engine
523#1,720,16815 redMay 19, 20252025 engine
524#1,731,90015 blackMay 19, 20252025 engine
525#1,737,11715 blackMay 19, 20252025 engine
526#1,756,97215 redMay 19, 20252025 engine
527#1,761,99615 blackMay 19, 20252025 engine
528#1,788,61515 blackMay 20, 20252025 engine
529#1,794,96715 redMay 20, 20252025 engine
530#1,800,26515 redMay 20, 20252025 engine
531#1,826,18815 redMay 20, 20252025 engine
532#1,828,25915 redMay 20, 20252025 engine
533#1,841,78815 redMay 20, 20252025 engine
534#1,847,79515 redMay 20, 20252025 engine
535#1,854,97915 blackMay 21, 20252025 engine
536#1,892,81315 blackMay 21, 20252025 engine
537#1,898,85815 blackMay 21, 20252025 engine
538#1,904,19415 redMay 21, 20252025 engine
539#1,906,35015 redMay 21, 20252025 engine
540#1,918,89115 blackMay 21, 20252025 engine
541#1,923,73015 blackMay 21, 20252025 engine
542#1,937,10915 redMay 22, 20252025 engine
543#1,947,92315 blackMay 22, 20252025 engine
544#1,975,14415 blackMay 22, 20252025 engine
545#1,978,78715 blackMay 22, 20252025 engine
546#2,001,03115 redMay 22, 20252025 engine
547#2,015,53815 redMay 23, 20252025 engine
548#2,029,45015 redMay 23, 20252025 engine
549#2,032,68315 blackMay 23, 20252025 engine
550#2,039,20315 redMay 23, 20252025 engine
551#2,041,72515 redMay 23, 20252025 engine
552#2,056,26715 redMay 23, 20252025 engine
553#2,100,55315 blackMay 24, 20252025 engine
554#2,110,42615 redMay 24, 20252025 engine
555#2,118,14915 redMay 24, 20252025 engine
556#2,120,35415 blackMay 24, 20252025 engine
557#2,128,06615 redMay 24, 20252025 engine
558#2,136,61715 redMay 24, 20252025 engine
559#2,154,45915 blackMay 24, 20252025 engine
560#2,167,74615 blackMay 24, 20252025 engine
561#2,199,58415 blackMay 25, 20252025 engine
562#2,221,02315 blackMay 25, 20252025 engine
563#2,240,60015 blackMay 25, 20252025 engine
564#2,259,03815 redMay 25, 20252025 engine
565#2,262,07415 redMay 25, 20252025 engine
566#2,296,39015 blackMay 26, 20252025 engine
567#2,302,70515 blackMay 26, 20252025 engine
568#2,313,80715 redMay 26, 20252025 engine
569#2,323,80515 blackMay 26, 20252025 engine
570#2,336,10515 redMay 26, 20252025 engine
571#2,337,73915 blackMay 26, 20252025 engine
572#2,344,45515 redMay 26, 20252025 engine
573#2,351,28515 blackMay 27, 20252025 engine
574#2,371,61615 blackMay 27, 20252025 engine
575#2,382,43615 redMay 27, 20252025 engine
576#2,409,30615 redMay 27, 20252025 engine
577#2,440,01215 redMay 28, 20252025 engine
578#2,466,40915 blackMay 28, 20252025 engine
579#2,466,89515 blackMay 28, 20252025 engine
580#2,481,71915 blackMay 28, 20252025 engine
581#2,483,22715 redMay 28, 20252025 engine
582#2,495,06715 blackMay 28, 20252025 engine
583#2,506,05615 blackMay 28, 20252025 engine
584#2,519,22015 blackMay 29, 20252025 engine
585#2,521,28515 redMay 29, 20252025 engine
586#2,529,91515 redMay 29, 20252025 engine
587#2,555,82915 redMay 29, 20252025 engine
588#2,633,06315 blackMay 30, 20252025 engine
589#2,635,37215 redMay 30, 20252025 engine
590#2,659,06015 blackMay 30, 20252025 engine
591#2,659,49815 redMay 30, 20252025 engine
592#2,668,61515 blackMay 30, 20252025 engine
593#2,716,15815 blackMay 31, 20252025 engine
594#2,725,01815 blackMay 31, 20252025 engine
595#2,728,65615 blackMay 31, 20252025 engine
596#2,739,79215 redMay 31, 20252025 engine
597#2,748,20615 redMay 31, 20252025 engine
598#2,752,12015 blackMay 31, 20252025 engine
599#2,763,07415 redMay 31, 20252025 engine
600#2,766,98015 blackMay 31, 20252025 engine

A run this long is not a sign of a bad shuffle. The GSR model page explains why a well-mixed deck still produces streaks, and how often.