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_50898 ( "Round" text, "St Kilda Saints" text, "Opposition" text, "Their Score" text, "Margin" real )

### Question ###
What is the average Margin that has a Round of 13. (h)?

### Accurate SQL ###

SELECT AVG("Margin") FROM table_50898 WHERE "Round" = '13. (h)'