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_4 (goal_difference INTEGER, goals_against VARCHAR, losses VARCHAR)

### Question ###
What is the average goal difference with 51 goals scored against and less than 17 losses?

### Accurate SQL ###

SELECT AVG(goal_difference) FROM table_name_4 WHERE goals_against = 51 AND losses < 17