What is a bent tab strike?

A bent back strike is a strike where during the forming process, all of the material where the openings for the latch and/or deadbolt was not removed leaving a "tab" of material which is then bent back at approximately 90°. See illustration

The bent tab strike helps a lot in openings where there is a load on the door.  Overcoming the load with a lever that you can get your whole hand on is easier than pushing at a point on the paddle, especially if you're not pushing at the end of the paddle.  Paddles that face down are pushed on towards the middle or top which reduces the force applied, a bent lip strike would be beneficial in this application.  Push paddles pointing up allow more leverage as most people will push at the top edge of the paddle.

The design of a bent tab strike has a smooth surface for the latch to move against whereas the standard strike has sharp corners pressed against the latch when there is a load on the door.  The normal forces against the latch created by a loaded door are reduced with the bent tabs.