The Pt-catalyzed hydrosilation reaction between methyl-substituted cyclosiloxane and a nonconjugated diene system produces silicone-carbon polymers with good mechanical and dielectric properties. In this work a statistical model is devised that provides a theoretical description of the polymerization reaction up to the B stage. An ensemble of cyclosiloxane molecules is built up in a computer and allowed to "react" with the diene (or mixture of dienes) in a Monte Carlo process. Included in the model are options for batch or semibatch operations. Through computer simulation, the concentrations of all molecular species at different conversions (as measured by the residual Si-H group) can be predicted as well as the molecular weight distribution. Good agreement is obtained with observed analytical data. The model is flexible and is used to study the effects of the changes in reaction process conditions on polymer structures and molecular weights.