I don't see a precise answer here, but an interesting question:http://www.militarytimes.com/article/20140612/NEWS08/306120062/How-did-800-ISIS-fighters-rout-2-Iraqi-divisions-
How did 800 ISIS fighters rout 2 Iraqi divisions?
Jun. 12, 2014
An image from a video posted by a group supporting the al-Qaida breakaway Islamic State of Iraq and Syria (ISIS), which has been verified and is consistent with other AP reporting, shows a militant in front of a burning Iraqi army Humvee in Tikrit, Iraq. (The Associated Press)
By Andrew Tilghman and Jeff Schogol
But the Islamic State of Iraq and Syria, or ISIS, apparently has routed an estimated 30,000 Iraqi Army soldiers who were trained by the U.S. military and given billions in sophisticated American military equipment.
The stunning outcome reflects widespread desertions among the Iraqi units in the north as well as the Sunni-Shiite sectarian tensions that underlie the military battles, experts say.
“It’s a relativity small force that managed to take the city [of Mosul], and it’s shocking that they were able to do that,” said Charlie Cooper, who studies Islamic extremism for the Quilliam Foundation in London.
“To me, that suggests there is collusion or at least deliberate capitulation on the part of Sunni tribes in western and northern Iraq,” Cooper said. “It’s likely that this happened because Sunni tribes in the area let it happen.”
Check this ISIS slideshow. Contains pics of US made military material taken from #Iraq army: http://t.co/zng3UAKRCY