This is a Scottish slang, which can only be found in the Encyclopedia of English. It sounds like Troy, not Troy, but cheers. Of course, the word Troy is internationally used, and its pronunciation is crooked when it is passed, so many of the words it is called now are tone sandhi versions, but different athletes in China also have different names.
For example, ZhangJike likes to shout "yo" or "ho" for a long time (similar to the pronunciation of "yo"). There is a small rule when he shouts: if he shouts "yo" for a short time, it means that he has not fully entered the state, so cheer for himself at this time. If you shout "roar" for a long time, it means that you hit a domineering ball in a passive situation, which means that the momentum has risen.