A baseball statistician finds that his team uses a left-handed pitcher 90% of the time against an opponent. Of the times that the team uses a left-handed pitcher, 20% result in that team winning the game. On the other hand, 70% of the time that teams use a right-handed pitcher results in winning the game. According to the data that informed these probabilities, what percent of all the games won against this opponent were games in which a left-handed pitcher was used?