Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_84 (round VARCHAR, event VARCHAR)
### Question:
How many rounds did Brett go for the Strikeforce: Shamrock vs. Diaz match?
### Answer:
SELECT round FROM table_name_84 WHERE event = "strikeforce: shamrock vs. diaz"