When bas van erp was the athlete what was the quarterfinals?
CREATE TABLE table_18602462_21 (quarterfinals VARCHAR, athlete VARCHAR)
SELECT quarterfinals FROM table_18602462_21 WHERE athlete = "Bas van Erp"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_18602462_21 (quarterfinals VARCHAR, athlete VARCHAR) Question: When bas van erp was the athlete what was the quarterfinals? [/INST] SELECT quarterfinals FROM table_18602462_21 WHERE athlete = "Bas van Erp" </s>