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_25251 ( "Stage" real, "Winner" text, "General Classification" text, "Mountains Classification" text, "Sprint Classification" text, "Team Classification" text )

### Question ###
Name the sprint classification being alejandro valverde

### Accurate SQL ###

SELECT "Sprint Classification" FROM table_25251 WHERE "Winner" = 'Alejandro Valverde'