Make sure you understand materials on time because lecture pace is fast. Don't procrastinate. He expects you to not only apply proved theorems in class and homeworks, but also understand the ideas behind those proofs. Watch out as these ideas will appear in exam question.

Exams are tough. He gives practice exams. I suggest you work through these practice exams, as you will have a great advantage on the actual exams.

If you have concerns/questions, it's better to ask him during OHs instead of emailing/piazza. It may feel a little intimidating, but he's willing to explain a concept until you get it. He is a very kind soul.

Take this course with this professor. I had Christou for 100B for about a week before dropping to take it with Padilla instead and that was one of the best decisions I could have made. Lectures are so much clearer, evenly-paced and informative; he does go a little fast through his slides but he always stops to make sure everyone is on the same page and to see if anyone has questions. Homework assignments are on the tougher side but are very doable, and he gives you a lot of time to do them; exams are tough but he provides a lot of practice exams that are pretty comparable in difficulty. Padilla is a good guy with a big heart, he never made me feel stupid for asking questions and was able to explain things very clearly and kindly as long as you ask for clarification on things that you are unsure on. Don't get the hype about Christou after having had both, Padilla is light years better. And in the end as expected the curve was very generous. Would recommend for anyone trying to get through the hell that is 100B.

This class is difficult, but it is pretty fair. It took a little while for me to get used to the prof's teaching, mostly because I find it a bit difficult to understand math just from powerpoint slides. Also, the pace of the lectures were fast and I would fall behind with writing things down. Overall though, I think he's good at explaining things and provides pretty thorough examples of the material.
Some cons: he's not very good at communicating, for example there's only one office hour a week and he was pretty much unresponsive to the piazza the entire quarter which was frustrating as there weren't many avenues to reach him about questions/concerns. also, he would get mad at our lecture when people weren't answering questions he was posing, which I get is annoying but also this is online school, so what do you expect lol

He's a very straightforward and curt professor. Pretty much no-nonsense kinda guy. This class is extremely hard regardless of who you take, and it was also the class that made me drop the Stats minor (peep the P/NP grade). It was even harder because I had Schoenberg for 100A who in no way prepares you for this class. Surprisingly I got Bs on the midterm and final because the TA grades very generously and just added like 11 points to everyone's grade for no reason.

He gives 30% As, 30% Bs, 30% Cs...so just aim for higher than the mean every time and you should be chilling. Definitely would not take a class with him again because he's too strict for my liking, but at the end of the day, if you put in any effort, you will be rewarded accordingly and he has your best interests in mind.

I recommend Stats 100B with this professor. His lectures are very clear and teaching this class is probably difficult but I felt I was able to follow the harder concepts. He constantly stopped to ask if we had questions which I appreciated because sometimes he went through the material really quickly. It seems like he cares about whether students are learning since he was willing to go over stuff again if someone was confused.

The exams are very difficult but the grading scheme (like the one the other person mentioned) of a certain percentage getting A's, B's, C's, and so on makes the grading more lenient. So if you think you did badly on an exam your actual grade won't necessarily reflect that. It seems like a lot of 100B classes have that in common though.

An overview of the class: grade consists of 5-6 homework assignments (20%), midterm (30%) and final (50%). For spring he made an accommodation allowing the final to be optional.

Very very good and clear and straightforward professor, you really probability learn from each slides. Taking his class is like fighting on a battlefield, you need to be concentrated every moment. Padilla is kind and patient, he answers every question students asked, no matter how detailed or silly it is. The exam is not that hard, it may need some smartness, but if you pay attention to his implication in class and go over examples he gave, you really get the exam. I prepared fully for final exam and when I looked at the questions, I felt like "what, it's just it?". Several questions are really easy, and others are doable. Regarding midterm, it's harder because time is limited. The last one was about proof, I had method but no time to finished. Overall, definitely recommend him!

Great lecturer and a useful class, but very difficult exams

Does not record class. Is very clear and will answer any questions you have. Very cut and dry, but is very knowledgable and will teach a lot. Maybe it was because of our TA but our exams were graded very easy. But it doesn't matter because he gives top 30% of class an A, second 30% a B and so on

I took this class in Winter 2020, and it was his first time teaching it. At the time, his slides were sometimes a bit unorganized and had typos, but he was usually able to fix it. His homework was hard but manageable, although the midterm was pretty difficult. In the end, he curved the class to a reasonable level (top 30% in the A to A- range), and the final was made optional for those who took the midterm due to the coronavirus situation that happened near the end of the quarter. Overall, I'd say he was a pretty decent professor for his first quarter teaching this class. Stats 100B is a hard class regardless, but Padilla made this class manageable.