In the NBA, determining the league's top defenders is often an incredibly difficult task. This is because superior defensive skills are still not completely understood by NBA executives much less fans.
Are blocks and steals what makes a player a good defender? Is it the ability to draw a charge? Or, is it merely putting pressure on the opposing player? Also, how much should defensive rebounds factor into the equation.
As of this time, it's hard to say what exactly is required of a great defensive basketball player. That said, I will now select the players whom I feel exhibit the best defensive characteristics in each of the relevant categories.