Last weekend in StarCraft, the world championship at IEM Katowice 2023 saw a so-good-it-must-be-scripted Cinderella story, where Oliveira won the world championship in a totally unexpected way. It was a whole roller-coaster of upset after upset from Oliveira, and up until the grand finals we were all still asking, “this can’t be, is this really happening?”.

Some context: StarCraft has one of the lowest upset rates of any competitive game out there, and Oliveira (formerly known as TIME) was ranked something like #21 coming in. Last November at DreamHack Atlanta (which I was at!), he didn’t win a single map. And just a month before IEM 2023, Blizzard had shut down its Chinese servers. But he’d been practicing 12 to 15 hours a day lately, and it showed.

The final winner interview was so emotional not only did Oliveira start crying, the host also started crying …

I’m happy to thank 日本評論社 and their team (Fuma Hirayama, Yuki Kumagae, Taiyo Kodama, Ayato Shukuta, among others) for making the Japanese translation a reality. As well as tripling the length of the errata PDF :)

This marks the second translation of the EGMO textbook (a Chinese translation was published a while ago as well by Harbin Institute of Technology). Both linked below:

• Japanese translation at nippyo.co.jp and amazon.co.jp. ISBN-10: 4535789789 / ISBN-13: 978-4535789784.
• Chinese translation at abebooks and amazon. ISBN-10: 7560395880 / ISBN-13: 978-7560395883.

This is a retro-post for the Mystery Hunt 2023, for which I played a somewhat minor role on the organizing team (teammate). You can play at interestingthings.museum.

There is an ongoing list of write-ups about the hunt being kept at puzzles.wiki, and you may also be interested in the reddit AMA from teammate.

Puzzle shoutout list

Favorite puzzles

The obligatory list.

• Hall of Innovation round
• You’re Telling Me (Atrium)
• Showcase (Atrium)
• Lost to Time (Basement)
• 5D Barred Diagramless with Multiverse Time Travel (Böotes)
• Subterranean Secrets (Basement), but this puzzle required being on-campus

Puzzles I am an author on

• Much Ado About Nothing (Atrium)
• Diagramless (Office), with Lumia Neyo.
• Circuit (Basement), with Jacqui Fashimpaur.
• Zambonis (Office), with Catherine Wu, Nicholai Dimov, and Steven Silverman
• 4D Geo (Wyrm), with Austin Lei, Moor Xu, and Nathan Wong
• Flooded Caves (Wyrm), with Alex Gotsis and Cameron Montag

Also a …

There’s a common error I keep seeing on OTIS applications, so I’m going to document the error here in the hopes that I can preemptively dispel it. To illustrate it more clearly, here is a problem I made up for which the bogus solution also gets the wrong numerical answer:

Problem: Suppose $a^2+b^2+c^2=1$ for positive real numbers $a$, $b$, $c$. Find the minimum possible value of $S = a^2b + b^2c + c^2a$.

The wrong solution I keep seeing goes like so:

Nonsense solution: By AM-GM, the minimum value of $S$ is $S\ge 3\text{exception 25:}$

A while ago someone asked me how COVID had affected the students I worked with. I replied that, on average, the pandemic had tripled my students’ productivity.

And I’m gonna brag about it like the proud teacher I am.

Couple Thanksgiving presents for y’all:

Errata List now on GitHub

The list of errata is now version controlled on GitHub: vEnhance/egmo-book-errata. So now you can actually see a changelog of the ocean of typos as they come in.

Shout-out to the crew working on the Japanese translation of the book for finding way more errors than I will ever care to admit (I didn’t count, but it’s probably in the 200-300 ballpark).

Automatically Generated EGMO Solutions Treasury (AGEST)

I took a snapshot my database entries for sourced problems in EGMO. It turns out that I have many written up already, so we now have something of a solutions manual for about half the problems or so. Since I like idiotic names, I dubbed it the Automatically Generated EGMO Solutions Treasury.

You can download it here: web.evanchen.cc/textbooks/AGEST.pdf

Some people have asked me why I anti-recommend JavaScript for beginners on my website FAQ. This post will try to give a few reasons why.

Some notes:

• I’m referring to base JS. I like TypeScript a lot for example (it’s high on my tier list of programming languages for beginners). And I know about eslint, but you asked me about recommendations for beginners, and I think beginners shouldn’t have to worry about setting up an IDE with strict linting until after they can write a for loop by themselves without screwing up.
• I have multi-file projects in mind. I don’t have a problem with using inline JavaScript for tiny 20-line snippets of code embedded in a webpage.
• I’m an amateur programmer. Professional programming is a different ball game.

Weak typing

I’m clumsy. I make many more mistakes than the average programmer. The other day …

don’t ask why it just came in my head

Quandary

So you have a fair coin that you found on the ground,
or at least that’s what everyone says.
But on each of N times that you’ve tossed it around,
you see every flip has been heads.

For which value of N should you start to suspect
that the coin isn’t actually fair?
For which values of N can you firmly declare
that the tails side is not even there?

By popular request, Twitch Solves ISL is renewed for a second season which will begin on Friday, 18 November 2022.

As in the past, streams will start at 8:00pm Eastern time on Friday nights, and last 1-4 hours depending on how much coffee I drank that morning.

I’ve scheduled 26 episodes for the second season to follow anime standards; this will last up through the spring semester of MIT, around May 2023.

That said, my holiday plans are to-be-determined so things are likely to change around a bit around the end of December or early January. The stream scheduled for 13 January 2023 is also likely to be modified due to the 2023 Mystery Hunt, which I’m nominally on the organizing team for (though I’m only helping a little bit this year).

Tune in! https://twitch.tv/vEnhance :)

To all my loyal viewers —

After two years, 480 hours, and 102 episodes of Twitch Solves ISL, I’ve finally decided that it’s time for me to take a hiatus from my weekly Friday night streams. So, episode 102 will be the end of Season 1.

To answer the obvious question: I’m definitely open to having a Season 2, although it will probably have to wait until after the summer (as I will be away from my stream setup then), and it probably won’t last 100 episodes. Between now and then, I might also sporadically stream video game sessions if I’m in the mood for it, so if you come by Friday night, you might get to watch me play through something from my Steam library.

I’d like to thank all my viewers and 1800 followers on Twitch, for being such a great audience all …