Hi, Abe. Let's put it this way. Kaloyan single-handedly destroys the 4th Crusade.

Kavhan: the element that I believe to be crucial is the initial engagement the day before. The Latins learn not to chase the Cumans, publicly commit themselves not to do so, and then do anyway. You can't posit that they were total idiots, since they'd just taken Constantinople. That means the Cumans are bringing something to the table that the Crusaders can't handle...

but I withdraw my headbanging, b/c you clearly know your stuff.