The strong safety in today’s game has to be more versatile than in the past.
Traditionally, this position provided run support by filling a gap between the three linebackers, provided pass coverage of the tight end, and played over the top of the cornerback in the 2-deep zone.
Modern NFL offenses line up in both unbalanced and balanced formations, and many now use the pass to set up the run. Many NFL defenses now utilize four linebackers instead of three, meaning the strong safety is more likely to float to the ball on running plays rather than exercise gap responsibility.
In short, the modern strong safety must be as adept at complex pass coverages as he is at stopping the run. While he still must have the strength to handle the tight end, he also needs the athletic ability to stay with a wide receiver, particularly on deeper routes.