Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_21602734_1 (league VARCHAR, year VARCHAR)

### Question ###
What league was involved in 2010?

### Accurate SQL ###

SELECT league FROM table_21602734_1 WHERE year = 2010