The Free Safety is normally the deepest defender on the field. He is similar to a center fielder in baseball. He’s the last line of defense as they say. Responsible for making touchdown-saving tackles on ball carriers breaking through the defense, he’s also the defender who protects the deep area of the field in the passing game.
The free safety has excellent range to roam from sideline to sideline. The more speed he has the better. The quarterbacks of the defensive backfield, they make the coverage calls and any defensive audible for the secondary.
They’re also athletes with great field scope, meaning they can keep the whole offense in their field of vision. They know how to attack the ball carrier at an angle to close quickly and insure a solid tackle.
A free safety may not be involved in as many plays as the other defenders. The plays they make can be game-saving passes defensed or game-saving tackles.
These players are rarely recognized and when they are, it is sometimes for missed opportunities rather than for great plays. The free safety is an unheralded yet critical element of a great defense.
Key offensive and defensive positions are described for new football fans in my book.