A system for estimating a velocity of a stress wave induced in a log or tree stem is used to maximize the value of wood products produced. An accelerometer is placed against the log while the log is struck with a pneumatic hammer. By monitoring the signals received at the accelerometer, the velocity of stress wave can be determined. Based on the velocity, an estimate of the modulus of elasticity (MOE) for the wood in the log is made. A price table is selected that relates different sizes of lumber having the determined modulus of elasticity to a current market value. The log is then cut such that the value of the lumber produced is maximized.