1. A process to predict the PENT value of a resin prepared using a specific catalyst system comprising determining the PENT values for a number of different resins prepared using the specific catalyst system, determining for each of the resins for which a PENT value was determined one or more of: 1) the percent of the heat capacity to melt the fraction of the polymer over the range from 90° C. to a set point relative to melting the entire sample at a heat up rate of 15 to 25° C. per minute which sample has been conditioned by successive self nucleation and annealing over the temperature range from 30 to 150° C. by heating and cooling the sample at a fixed rate from 70 to 95° C. per minute over the temperature range in decreasing increments of upper temperature from 5 to 10° C. provided that at least one increment is the set point; and 2) the percent of the heat capacity to melt the fraction of the polymer over the range from a set point to 140° C. relative to melting the entire sample at a heat up rate of 15 to 25° C. per minute which sample has been conditioned by successive self nucleation and annealing over the temperature range from 30 to 150° C. by heating and cooling the sample at a fixed rate from 70 to 95° C. per minute over the temperature range in decreasing increments of upper temperature from 5 to 10° C. provided that at least one increment is the set point; and plotting the results of the % heat capacity of 1, 2 or both as a function of the PENT values to generate a calibration curve.