Playing the high post and the low post
We often think of bigs as a homogeneous group, filled with physically-imposing players who enjoy a good, bruising battle under the basket. However, when we take a look at the best frontcourt players of all-time, we start to realize that there is considerable variety in their playing styles. Most notably, post players can be split into the high post and the low post, with very different functions.
Low post players are the traditional bigs who ply their trade at the bottom of the paint, close to the basket. As such, low post play tends to be more physical as players jostle for position. Allowing a big man to establish position down low is akin to giving up an easy basket, due to the proximity of the rim. Core strength and stability are necessary on both offense and defense, to bang your way in or to hold off the defender for the lay-up or hook shot and to prevent your opponent from doing the same. Low post players usually play with their back to the basket due to the close contact, and can easily draw fouls or a double team with a quick move inside.
High post players operate at the top of the painted area, around the free throw line. It is usually easier to receive the ball at the high post, especially with a combination of height, length and athleticism. Thus, many set plays begin with a pass to the high post, as compared to the isolation-heavy nature of low post play. The post player can often play face-up, allowing him a clear view of the entire floor and opening up many passing opportunities and angles. As a result, high post players have to make more decisions on offense and rely more on finesse or guile, and generally need to be able to knock down the mid-range shot.
It is clear that there are advantages and disadvantages to both aspects of post play, and thus an ideal post player should be able to play both positions. If your bigs are equally versatile, they can operate in a high-low motion-type offense, essentially playing interchangeable roles. Tim Duncan and David Robinson perfected this system while starring together for the San Antonio Spurs.