The most plausible?
Probably the assassination of FDR, seeing as it nearly happened IOTL.
I just want to see the Crusaders successfully cross Anatolia, who would have thought that would be so friggin diificult.
The First Crusade did it, as did Barbarossa. The Komnene army used to go back and forth like a walk to the shops.
The peoples Crusade which had a reasonable armed contingent, the Crusade of 1101 which had 3 armies and the 2nd which had 2 armies, so the Turks destroyed maybe 5 or 6 armies all up.