Attrition is usually considered as an undesired process. Therefore, many researchers devoted their work to find ways for reducing the attrition. However, attrition might be controlled by understanding the parameters and mechanisms affecting it. The control could be realized by reducing the attrition, increasing it, or conducing a selective attrition that will change the particle's shape. In this paper, the attrition mechanism is explained and analyzed. Possible ways, to either increase or decrease the attrition, are described. Experimental results of a new system for selective attrition are shown in more details.