This study investigates the impact of 2006 NFL rule change on the 2015 DeflateGate controversy. This analysis contributes to the discussions surrounding Tom Brady, the Patriots and their role in game day football preparation. This study is unique in that the analysis using game and play level data looks at a rule change that previously had not been analyzed. The methodology used in this research is difference in difference regression analysis. The variable of interest is the interaction term between team effects and time effects. This study investigates the effect of the rule change on fumble statistics and passing statistics on offensive plays for visiting NFL teams. The study finds support for the claim that the 2006 rule impacted football preparation for Tom Brady and Peyton Manning, and football preparation for the New England Patriots and Indianapolis Colts. Both these quarterbacks and teams substantially improved their offense’s ability to fumble less after the rule change. Other teams and quarterbacks did not experience this effect.