Among the role playing game genre, how many are targeted to teens and what is their average sentiment polarity score?
targeted to teen refers to Content Rating = 'Teen'; average = AVG(Sentiment_Polarity);
SELECT COUNT(T1.App), AVG(T2.Sentiment_Polarity) FROM playstore AS T1 INNER JOIN user_reviews AS T2 ON T1.App = T2.App WHERE T1."Content Rating" = 'Teen' AND T1.Genres = 'Role Playing'