Was the a decline in the quality of Mongol troops and leadership as time went on?

Nov 2014
Was there any conclusive evidence for a decline in quality on Mongol cavalry troops and leadership between the time of Genghis/Ogodei and by the later part of the 13th century under Genghis' grandsons, around the time of Ain Jalut and the subsequent Mongol raids into Europe where the Mongols started to look beatable? Also what tactics and weapons did the Southern Song resort to when fighting the Yuan army, aise from trying to outlast the Mongols in city sieges and using rockets and explosives against the Mongols?


Ad Honorem
Jun 2012
Well, cud hv been that they were kind of like Brazil, Germany or Argentina at the WC. One day, someone found out that they weren't really invincible, after all. So, eventually, even the Belgiums or the Croatias started whuppin them.