Top dog v Dark horse meaning difference [closed]

Could someone explain the difference between these 2 above please? Upon its win does a dark horse then become a top dog?

Would a dark horse be more similar to an underdog?

My first post on this site. I’m not a linguist, but I’m interested in linguistics. The terms in question do not have the same meaning. They are all common terms used in the Sports vernacular. Top Dog refers to a competitor or team that has achieved dominance in a particular area, like the New York Yankees in a good year. Dark Horse is usually used to describe an individual or team that “came out of nowhere” to achieve success, but was previously underrated. Underdog is an individual or team that is statistically underrated, and not expected to succeed. It does not imply future success. It’s meaning is similar to underrated.