Petrov is great! Your grade in the class consists mainly of 7 quizzes, with the lowest score dropped. It's not hard to do well on the quizzes if you put effort on the homework assignments and make good cheat sheets. The concepts themselves are interesting, and topics such as martingales and Brownian motion appear in fields such as finance. Mr. Petrov is also very approachable outside of class and is clearly passionate about probability theory.