I have defrag MyISAM (Majority) and InnoDB (Minority) tables in MySQL multiple times today. Dropped from 70+ to 11 (lowest) and then climb back to 30-40 in an hour or two time.

How to constantly defrag tables or identify what is causing the defrag?

Hello

The best thing that you can do is to convert all tables to Innodb .

You will benefit a lot.