Statistical effects of changing the number of strategic missiles carried on each missile submarine are explored in this study. The number of submarines required so that a specific number of missiles will survive an enemy 'first strike' and be available for retaliation is determined using a simple binomial model of survival. The measures of effectiveness used are (1) the numbers of submarines and missiles initially required in the submarine-missile system and (2) the total system cost. It is demonstrated that changes in submarine neutralization probability could be the dominating factor in selecting submarine size. A statistical basis is provided for evaluation of potential changes in this neutralization probability.