Summer of Math Exposition

How many times do you ACTUALLY need to shuffle?

This video is a deep dive under the hood of the commonly-held belief that you need to shuffle a deck 7 times before it's random. We discuss what this statement actually means, and how to mathematically prove something like this.

Analytics

6.9 Overall score*
39 Votes
9 Comments
Rank 14

Comments

There are several aspects that I just adored about the video. First and foremost, the topic itself, since randomness is really relevant these days... It is a big part of many areas of science and technology, like cryptography! I think it could have been a good idea to mention some of these areas, but I guess you wanted to focus the attention to the cards, since it was the "leading" problem there. Also, I liked the way you structured the video, it was easy to understand where to come back if you didn't understand one part. In other words, the approach that you used was really pedagogic in some sense. One could follow the steps of your explanation but the topic itself is not easy and I would argue that the first half of the video could intimidate many. You made a really great job explaining some of the prerequisites, like what is a distribution, but I think you could have recalled the various definitions more often. For example, saying again what was the "distance" between the two decks or what was the correlation between the random deck/normal deck and the formula for the distribution. I really liked the fact that you mentioned some other related problems, such as the Birthday problem and the ending reference for the paper. These were really incentive moments for further exploration. All in all, I think that your video is really a good base for any statistics lesson, mostly for the structural approach that you used. Indeed, these topics are complex, and your video reflects that in some sense. I believe that everyone could understand the concepts you presented after whatching the video 2/3 times and that the video itself answers many of the questions that arise from it. Good job!

7.7

Amazing video! Great hook, visuals (color scheme is golden), extremely clear. I, myself, was extremely drawn to watch the entire video. I always wondered why other videos said you should shuffle the deck 7 times. Very memorable video. Now I'm even more excited to take a graduate probability course! The weakest point I'd say is that this video is best for those who have taken a basic probability course. Others might get lost in the definitions of random variables and probability measures, but not much you can do about this.

8.9

Generally liked the problem and the explanation, but it was a bit hard to follow the reasonings at the end.

6.1

Good content and communication. Only thing is that with respect to communication, I felt that the author spoke too quickly, making it more difficult to understand without pausing the video.

7.1

The video started very well and I found it clear enough to follow, but before even the half way mark I quickly got lost in what was being shown and could no longer follow the video. It is possible that this simply isn't aimed at someone with my mathematical ability (although not stated what the level is) so I am willing to give him the benefit of the doubt and say that it is a good video. I also was very interested in the mathematical topics and did find the parts I could follow quite exciting.

6

Truly well made. I heard that in order for a deck to be truly random you would need 7 shuffles. However, I never new mathematically how that come about. It's great that you gave further reading as well for anyone who's interested. The visuals and math expressions were spot on.

7.7

Simply an amazing video! Probability ain't my strong suit, bit after watching this, I might get back into it.

8.8

This is my favorite SoMEπ submission hands down.

9

Great video. Funny, interesting, clear. Well done.

8.5