What if the Mongol conquests had gone differently?

In two generations the Mongols build the largest contiguous land empire in history.

If it had gone differently: Eurasia is never briefly stitched into one zone; goods, ideas, and the plague all travel far slower between China and Europe.

1. 1000Medieval China's commercial boom, China's medieval takeoff stalls; paper money, the compass and gunpowder stay isolated curiosities for centuries.
2. 1347The Black Death, Serfdom and a land-rich, labour-poor order roll on; wages stay flat and the church's authority unshaken.
3. 1450The rise of the Ottoman Empire, The eastern Mediterranean stays contested and open; no single power can tax or close the road to the East.