Word Game Trivia ~ 'GOAT'

In sports what could the abbreviation 'GOAT' mean?
See if you're able to guess before getting the the last picture.

===.
Clue 1

===.
Clue 2

===.
Clue 3 ~ You should get the answer by now.

===.
Clue 3 ~ Yes, definitely the answer by now.

===.









===.
Source:
http://eletter.multiply.com/photos/album/9/Word-Game-Trivia-GOAT

===.