Abstract: The present invention relates to a system and method for practically measuring cycle by cycle repeatable system behavior. A set of system parameters is selected for tracking by a group of counters which preferably operate to condense the system state trajectory into a manageable set of counter values thereby forming a counter state. Preferably, repeatability of the counter state practically assures repeatability of the system state trajectory. System repeatability is helpful for debugging purposes since definite identification of a system defect is made easier when a test program failure caused by exercising a defect is repeatable. A test program may be varied for successive runs on a computer system by employing a different randomly or pseudo-randomly generated seed for each run and preferably exercising as many features of the computer system as possible in order to search for defects in the computer system.