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_23691 ( "Club" text, "Played" text, "Won" text, "Drawn" text, "Lost" text, "Points for" text, "Points against" text, "Points difference" text, "Bonus Points" text, "Points" text )

### Question ###
when the points for is 139 is points difference?

### Accurate SQL ###

SELECT COUNT("Points difference") FROM table_23691 WHERE "Points for" = '139'