My understanding for the pronunciation of 將 is 4th tone for verb (e.g. 將數百之衆，轉而攻秦) and 1st tone for noun (e.g. 將軍; 將 in 象棋).
So why is it that for 上將 as in 海軍上將, the character is in 4th tone? My hypothesis is that it is from the usage of 將領 as a noun without a change in tone?
Interesting question. Why change tone?
English is called a stress-timed language. In English, we often shift the stress to change from verb to noun as in:
v. produce, n. produce, v. refuse, n. refuse
I wonder if this is also generally true for Chinese? It is worth looking into.
"My understanding for the pronunciation of 將 is 4th tone for verb " you may be a little confused there.
jiāng has a lot of possibilities. Here are some.
jiàng does not have so many, but, for simple cases, it is nominal in nature.
1. 军衔的一级，在校以上，泛指高级军官：～领。
2. 统率，指挥：～百万之众。
This link has so many uses for 将 you could get dizzy! There is no clear distinction verb/noun -- jiāng/jiàng
btw is Vibius Vibidius Zosimus really your name?
Generally, in modern Chinese, 将 is a noun when it pronounced as jiàng, and a verb as jiāng.
However, in traditional Chinese, 将 jiàng could be used as verb, meaning 统率，指挥, leading as a general. Say, 将百万之众.
将 jiàng as a noun means 'senior general' or 'high-ranking officer' in military.
將軍 or 將 in 象棋 are pronounced as jiāng when it means to check (attacking to 將 jiàng). A chess man in 象棋 is called 將 jiàng as a noun.
將軍 or 将军 (jiāng), as a set, can also be a noun, meaning general or admiral.
in 廣韻, 將 has two pronunciations:
one is in volume 2, lower level tone (下平聲), 陽韻:
將﹒送也﹒行也﹒大也﹒助也﹒辝也﹒又姓﹒後趙録有常山太守將容﹒即良切﹒又子諒切六
another one is in volume 4, departing tone (去聲), 漾韻:
將﹒將帥﹒子亮切
according to the usage, difference tone was used for long time.
most of the time, when 將 is used as verb, adjective, or surname, it was pronounced as level tone.
when it was used as noun, in a military title, it was pronounced as departing tone.
have fun :)
