It has become so popular for two reasons. The Zero sector is located at the top of the columns, and at the bottom are the column betting fields, with duplicate dozen betting fields on both sides. 
http://60.250.226.63/ipkb/viewtopic.php?f=41&t=1966819
https://muchroom.ng/index.php?topic=52113.new#new
http://www.horsecity.ru/phpBB3/viewtopic.php?f=33&t=220413
https://67farms.st/viewtopic.php?t=12328
http://1.s.2.free.fr/viewtopic.php?f=17&t=326095
https://my-mobile.eu/viewtopic.php?t=6168
https://ufr-2020.front5.picapo.net/forums/viewtopic.php?pid=557652
http://oldsite.giessen46ers.de/fantalk/viewtopic.php?f=5&t=196174
http://forexam.ru/component/kunena/?func=view&catid=5&id=174092#174092
http://mirosovak.edoras.cz/viewtopic.php?f=3&t=97067
http://users.atw.hu/tunedthings/viewtopic.php?p=441738#441738
http://www.horsecity.ru/phpBB3/viewtopic.php?f=5&t=256742
https://phantom.everburninglight.org/archbbs/viewtopic.php?pid=670663#p670663
http://www.lada-xray.net/showthread.php?p=213448#post213448
http://wirtualnapolityka.cba.pl/showthread.php?tid=9034
https://boards.streamweaver.app/showthread.php?tid=5205
http://frmklas.com.tr/threads/gry-online-automaty-sizzling-hot-oraz-kasyno-polska.103089/
http://vortex.mx.free.fr/forum/viewtopic.php?f=38&t=1691&sid=e24486364913ac183b250af6e7abdb8c
http://frmklas.com.tr/threads/tragaperras-dinero-real-mejor-app-para-ganar-dinero-jugando.114643/