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_1 ( round VARCHAR, position VARCHAR, pick__number VARCHAR )

### Question ###
In what Round was a Defensive Tackle Pick # less than 19?

### Accurate SQL ###

SELECT COUNT(round) FROM table_name_1 WHERE position = "defensive tackle" AND pick__number < 19