Quote Originally Posted by Geezer57
If I remember the old posts correctly, it's the first building listed in the UNIT_PROD file that provides the valor bonus when upgraded to Master level. No bonus if Master level is required to build the unit, and Royal buildings (needed for Knights) don't really have a "master" building - so Knights don't get a valor bonus for buildings, only provinces.

In the examples you gave, Caravel, the JI get a bonus for Master Swordsmith, and Futuwwa for Master Boyer. That's what has always worked for me.
That doesn't explain why Ghulam Cavalry get their valour bonus from the Master Horse Breeder, and not the Master Spearmaker. In their dependencies column in the unit prod file, the spearmaker is listed before the horse_breeder.

Knights do have a master level building but it can only be built by the HRE and Italians IIRC it does give a valour bonus, though I could be mistaken.