Abstract: A polymer pelletizing apparatus includes a device for automatically and electronically indexing (advancing) a set of pelletizer knives by a predetermined distance upon the expiration of a predetermined time period. This advancement is continued for the useful life of the pelletizer knives and is called the advancement cycle. The predetermined distance and predetermined time period are entered into a PLC. The PLC is connected to an external advancing device such that when the PLC determines that the predetermined time period has expired, the PLC causes the external advancing device to index or advance the pelletizer knives by a predetermined distance. This advancement cycle provides consistent wear of the pelletizer knives and accurately provides an estimate of the need for a knife change.