I should add that the mongols adapted their hunting style to warfare even further than KoA explained. The Mongol Armies faced many enemies with superior Armies, the difference is, is that the Mongolians would send scout forces ahead to probe an enemy's defenses, gather information on it's strength, and overall how to best destroy the force before the main Army ever made contact. Whereas other nations of the time would send in the Army, and at the field of battle would determine how to destroy the enemy, without any prior knowledge to an enemy's strength. The Mongolian's were ahead of their time, and had Orda not died, it's probable that the Mongols could've swept through most of Europe, instead after his death, there was little Organization due to the Empire's vast area of control, which gave surrounding nations time to adapt, and ultimately subjugate the former Empire's lands.