Research, analysis and identification of the reasons for the decline of bits performance in case of occurrence of such common and undesirable phenomenon as tracking (rack formation) at the wellbottom is an important aspect of studying the effectiveness of rock destruction by roller cone bits. Factors affecting rocks destruction efficiency at the bottom of the well have been theoretical studied. A mathematical model of roller-cone drill bits operation at the wellbottom has been created, which allows the development of new cutting structures of roller-cone drill bits, capable of effectively destroying rocks without tracking (rack formation). The main reasons and regularities of the tracking occurrence at the bottom of the well, which reduces the efficiency of rocks destruction, have been identified, methods have been developed to prevent or minimize it. An analytical model and a calculation scheme have been developed that allow obtaining reliable information about the parameters and operating conditions of individual roller cone bits and their rolling cutter teeth row at the wellbottom.