Conversation so far:
who has won back to back us open golf tournament
Seven players have won back to back US Opens.
can you tell me a player who has won the us open twice in a row
Brooks Koepka won the U.S. Open in 2017 and 2018.
who has won 3 us golf opens in a row
Willie Anderson holds the record for most consecutive US Open wins with three.
can you tell me about the championship structure of the us open
Since 1898 the US Open has been 72 holes of stroke play, with the winner being the player with the lowest total number of strokes.

Question: when does the championship happen
Self-contained rewrite: when is the us open