Do I have to be tall to be a competitive post player?

No. When the Chicago Bulls needed to score during their championship reign, they brought their forward and center out to the perimeter and posted up Michael Jordan. Why post up MJ? Often, guards make great finishers inside because of their footwork and touch. Six NBA championships later we know with certainly it worked for the Bulls. A dominant post player, regardless of size, can make all the difference. Mike Krzyzewski (Coach K.) did the same thing to get key baskets against Butler in the 2010 NCAA championship, dropping guard, Kyle Singler, into the post!