This story says 1800 Sanders delegates walked out!
http://www.cleveland.com/politics/index.ssf/2016/07/dnc_2016_bernie_sanders_suppor.html
“This story says 1800 Sanders delegates walked out!”
Well that would be nearly all of them, since Sanders had 1,893, including his 47 super delegates who probably would not walkout even if the place was on fire. So subtracting those delegates, leaves 1,846, and 1,800 of those walked out!