NFL's top game plan nightmares

Troy Polamalu has made a name for flying around the field and wreaking havoc. George Gojkovich/Getty Images

Putting together an NFL game plan is essentially a problem-solving exercise, but not all problems are created equal.

Some players have skill sets that make them extraordinarily difficult to figure out, and when they are on the defensive side of the ball, they can cause offensive coordinators to lose more than a few hours of sleep.

Here are four defensive players who currently fit that description the best in the NFL:

Troy Polamalu, S, Pittsburgh Steelers

Over the years, Polamalu has received a lot of well-deserved credit for his blitzing prowess, and that part of his game certainly hasn't diminished. Evidence for this could be found in Week 6 against the Jacksonville Jaguars, when Polamalu timed a blitz so perfectly that he got through Jaguars guard Uche Nwaneri and was able to hit quarterback Blaine Gabbert in barely more than three-tenths of a second after the snap.

As impressive as that ability is, what makes Polamalu truly dangerous is that he can cover just as well as he can blitz and tackle.