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_name_87 (field_goals INTEGER, touchdowns VARCHAR, player VARCHAR, points VARCHAR, extra_points VARCHAR)

### Question ###
When Herb Graver played, how many field goals were made when there were more than 50 points, less than 15 touchdowns, and more than 0 extra points?

### Accurate SQL ###

SELECT AVG(field_goals) FROM table_name_87 WHERE points > 50 AND extra_points > 0 AND player = "herb graver" AND touchdowns < 15