MIT Mystery Hunt 2019

Here is a lesson that should be obvious: if you are trying to hit a paper deadline, going to Mystery Hunt the weekend before that deadline is a bad idea. In my defense, I did not think we were submitting to ICML, but some last-minute results convinced us it was worth trying.

Combined with the huge airport troubles getting out of Boston, I ended up landing in California at 11 AM the day before the deadline, with the horrible combination of a ruined sleep schedule and a lack of sleep in the first place. But, now I’ve recovered, and finally have time to talk about Hunt.

I hunted with teammate this year. It’s an offshoot of ✈✈✈ Galactic Trendsetters ✈✈✈, leaning towards the CMU and Berkeley contingents of the team. Like Galactic, the team is pretty young, mostly made of people in their 20s. When deciding between Galactic and teammate, I chose teammate because I expected it to be smaller and more serious. We ended up similar in size to Galactic. No idea where all the people came from.

Overall feelings on Hunt can be summed up as, “Those puzzles were great, but I wish we’d finished.” Historically, if multiple teams finish Mystery Hunt, Galactic is one of those teams, and since teammate was of similar size and quality, I expected teammate to finish as well. However, since Hunt was harder this year, only one team got to the final runaround. I was a bit disappointed, but oh well, that’s just how it goes.

I did get the feeling that a lot of puzzles had more grunt work than last time Setec ran a Hunt, but I haven’t checked this. This is likely colored by hearing stories about First You Visit Burkina Faso, and spending an evening staring at Google Maps for Caressing and carefully cutting out dolls for American Icons. (I heard that when we finally solved First You Visit Burkina Faso, the person from AD HOC asked “Did you like your trip to Burkina Faso?”, and we replied “Fuck no!”)

What I think actually happened was that the puzzles were less backsolvable and the width of puzzle unlocks was smaller. Each puzzle unlocked a puzzle or a town, and each town started with 2 puzzles, so the width only increased when a new town was discovered. I liked this, but it meant we couldn’t skip puzzles that looked time-consuming, they had to be done, especially if we didn’t know how the meta structure worked.

For what it’s worth, I think it’s good to have some puzzles with lots of IDing and data entry, because these form footholds that let everybody contribute to a puzzle. It just becomes overwhelming if there’s too much of it, so you have to be careful.

Before Hunt

Starting from here, there are more substantial puzzle spoilers.

A few weeks before Hunt, someone had found Alex Rosenthal’s TED talk about Mystery Hunt.

We knew Alex Rosenthal was on Setec. We knew Setec had embedded puzzle data in a TED talk before. So when we got INNOVATED out of the TED talk, it quickly became a teammate team meme that we should submit INNOVATED right as Hunt opened, and that since “NOV” was a substring of INNOVATED, we should be on the lookout for a month-based meta where answers had other month abbreviations. Imagine our surprise when we learn the hunt is Holiday themed - month meta confirmed!

The day before Hunt, I played several rounds of Two Rooms and a Boom with people from Galactic. It’s not puzzle related (at least, not yet), but the game’s cool enough that I’ll briefly explain. It’s a social deduction game. One person is the President, another person is the Bomber, and (almost) everyone’s win condition is getting the President and Bomber in the same or different rooms by the end of the game.

Now, here’s the gimmick: by same room, I mean the literal same room. People are randomly divided across two rooms, and periodically, each room decides who to swap with the other room. People initially have secret roles, but there are ways to share your roles with other players, leading to a game of figuring out who to trust, who you can’t trust, and concealing who you do trust from people you don’t, as well as deciding how you want to ferry information across the two rooms. It’s neat.

Right before kickoff, I learned about the Mystery Hunt betting pool one of my friends was running, thought it was fun, and chipped in, betting on Palindrome. While waiting for puzzles to officially release, we printed our official team Bingo board.

Puzzles

Every Hunt, I tend to look mostly at metapuzzles, switching to regular puzzles when I get stuck on the metas. This Hunt was no different. It’s not the worst strategy, but I think I look at metas a bit too much, and make bad calls on whether I should solve regular puzzles instead.

I started Hunt by working on GIF of the Magi and Tough Enough, which were both solid puzzles. After both of those were done, we had enough answers to start looking at Christmas-Halloween. We got the decimal-octal joke pretty quickly, and the puzzle was easy to fill-in with incomplete info, then gave massive backsolving fodder. Based on the answers shared during wrap-up, several other teams had a similar experience.

Backsolving philosophy is different across teams, and teammate borrows a culture from Galactic - backsolve as much as you want, as long as you wait for your answer to be confirmed wrong before trying it for the next puzzle, and try to have only 1 pending answer per puzzle. This makes our solve accuracy relatively terrible since our frequent backsolve attempts drag down the average. For example, we guessed several random words for Moral Ambiguity, because we knew it thematically and mechanically had to be the Holi Day prank answer.

We got feedback to backsolve less aggressively and toned down our backsolve strategy by a lot. In fact, we completely forgot to backsolve Making a Difference. This was especially embarassing because we knew the clue phrase started with “KING STORY ADAPTED AS A FILM”, and yet we completely forgot that “RITA HAYWORTH AND THE SHAWSHANK REDEMPTION” was still unclaimed.

I did not work on Haunted but I know people had a good laugh when the cluephrase literally told them “NOT INNOVATED, SORT FIRST”. teammate uses Discord to coordinate things. Accordingly, our #innovated-shitposting channel was renamed to #ambiguous-shitposting.

I did not work on Common Flavors, and in fact, we backsolved that puzzle because we didn’t figure out they were Celestial Seasonings. At some point, the people working on Common Flavors tried brewing one of the teas, tried it, and thought it tasted terrible. It couldn’t possibly be a real tea blend!

Oops.

Eventually they cut open the tea bags and tried to identify ingredients by phonelight.

We See Thee Rise was a fun puzzle. The realization of “oh my God, we’re making the Canadian flag!” was great. Even if our maple leaf doesn’t look that glorious in Google Sheets…

I did not work on The Turducken Konundrum, but based on solve stats, we got the fastest solve. I heard that we solved it with zero backtracking, which was very impressive.

For Your Wish is My Command, our first question was asking HQ if we needed the game ROMs of the games pictured, which would have been illegal. We were told to “not do illegal things.” I did…well, basically nothing, because by the time I finished downloading an NES emulator, everyone else had IDed the Game Genie codes, and someone else had loaded the ROM on an NES emulator they had installed before Hunt. That emulator had a view for what address was modified to what value, and we solved it quickly from there.

I want to call out the printer trickery done for 7 Little Dropquotes. The original puzzle uses color to mark what rows letters came from, but if you print it, the colors are removed for Roman numerals, letting you print the page with a black-and-white printer. Our solve was pretty smooth, we printed out all the dropquotes and solved them in parallel. For future reference, Nutrimatic trivializes dropquotes, because the longer you make the word, the more likely it is that only one word fits the regex of valid letters. This means you can use Nutrimatic on all the long clues humans find hard, and use humans on all the short clues Nutrimatic finds hard. When solving this puzzle, I learned I am really bad at solving dropquotes, but really good at typing regexes into Nutrimatic and telling people “that long word is INTELLECTUAL”.

Be Mine was an absurd puzzle. I didn’t have to do any of the element IDing, which was nice. The break-in was realizing that we should fill in “night” as “nite” and find minerals, at which point it became a silly game of “Is plumbopalladinite a mineral? It is!” and “Wait, cupromakopavonite is a thing?” I had a lot of fun finding mineral names and less fun extracting the puzzle answer. I was trying to find the chemical compounds word-search style. The person I was solving with was trying to find overlaps between a mineral name and the elements in the grid. I didn’t like this theory because some minerals didn’t extract any overlaps at all, but the word search wasn’t going great. It became clear that I was wrong and they were right.

If you like puzzlehunt encodings, The Bill is the puzzle for you. It didn’t feel very thematic, but it’s a very dense pile of extractions if you’re into that.

Okay, there’s a story behind State Machine. At some point, we realized that it was cluing the connectivity graph of the continental United States. I worked on implementing the state machine in code while other people worked on IDing the states. Once that was IDed, I ran the state machine and reported the results. Three people then spent several minutes cleaning the input, each doing so in a separate copy of the spreadsheet, because they all thought the other people were doing it wrong or too slowly. This led to the answer KATE BAR THE DOOR, which was…wrong. After lots of confusion, we figured out that the clean data we converged on had assigned 0 to New Hampshire instead of 10. They had taken the final digit for every state and filtered out all the zeros, forgetting that indicies could be bigger than 9. This was hilarious at 2 AM and I broke down laughing, but now it just seems stupid.

For Middle School of Mines, I didn’t work on the puzzle, but I made the drive-by observation that were drawing a giant 0 in the mines discovered so far, in a rather literal case of “missing the forest of the threes”.

I had a lot of fun with Deeply Confused. Despite literally doing deep learning in my day job, I was embarrassed to learn that I didn’t have an on-hand way to call Inception-v3 from my laptop. We ended up using a web API anyways, because Keras was giving us the wrong results. Looking at the solution, we forgot to normalize the image array, which explains why we were getting wrong adversarial class.

Chris Chros was a fun puzzle. I never realized so many people with the name “Chris” were in Infinity War.

He’s Out!! was a puzzle that went from “huh” to “wow, neat!” when we figured out that a punchout in baseball means a strikeout. I’ve never played Punch-Out!!, but I recognized it from speedruns. A good intro is the blindfolded run by Sinister1 at AGDQ 2014.

Tree Ring Circus was neat. I felt very clever for extracting the ring sizes by looking up their size in the SVG source. I then felt stupid when I realized this was intentional, since it’s very important to have exact ring sizes for this puzzle.

Cubic was cute. It’s fune to have a puzzle where you go from, “ah, Cubic means cubic polynomials”, and see it go to “ohhhh, cubic means cubic graphs”. I didn’t really do anything for this but it was fun to hear it get solved.

Somewhere around Sunday 2 AM, we got caught by the time unlock and starting unlocking a new puzzle every 15 minutes. I’m not sure what exactly happened, but the entire team somehow went into beast mode and kept pace with the time unlock for several hours. We ended up paying for it later that morning, when everyone crashed until noon. One of the puzzles solved in that block was Divine the Rule of Kings, which we just…did. Like, it just happened. Really weird. There were some memes about “can someone pull up the US state connectivity graph, again?”. Turns out puzzle authors really like that graph.

Of the regular puzzles I solved, I’d say my favorite was Getting Digits. We didn’t hit all the a-has at once, it was more like a staggered process. First “ON and OFF!”, then “Ohhhh it’s START”, then “ohhh it’s a phone number”. It’s a simple extraction but there’s still something cool about calling a phone number to solve a puzzle.

Metapuzzles

Despite looking at a lot of metas, I didn’t contribute to many of them. The one where I definitely helped was figuring out the turkey pardon connection for Thanksgiving-President’s Day. Otherwise, it was a bunch of observations that needed more answers to actually execute.

This section really exists for two reasons. The first is the Halloween-Thanksgiving meta. We were stuck for quite a while, assuming that the meta worked by overlaying three Halloween town answers with three Thanksgiving answers with food substrings, and extracting using blood types in some way. This was a total red herring, since the food names were coming from turkey names. However, according to the people who solved it, the reason they finally tried ternary on the blood types was because we had a bingo square for “Puzzle uses ternary in extraction”, and they wanted to get that square. I’m officially claiming partial credit for that metapuzzle.

The second reason is the Arbor-Pi meta. We had the core idea the whole time - do something based on digits after the Feynman point. The problem was that we horribly overcomplicated it. We decided to assign numbers to each answer, then substitute numbers based on answer length. So far, so good. We then decided that since there were two boxes, the answer had to be a two digit number, so we took everything mod 100. Then, instead of extracting the digit N places after the Feynman point, we thought we needed to find the digits “N” at some place after the Feynman point, noting how many digits we had to travel to find N. Somehow, of the 8 boxes we had, all of them gave even numbers, so it looked like something was happening. This was all wrong and eventually someone did the simple thing instead.

Post-Hunt

Since Palindrome didn’t win, I lost my Mystery Hunt bet. It turns out the betting pool only had four participants, we were all mutual friends, and we all guessed wrong. As per our agreement, all the money was donated to Mystery Hunt.

Continuing the theme of not winning things, we didn’t get a Bingo, but we got very close. At least it’s symmetric.

After Hunt ended, we talked about how we didn’t get the Magic: the Gathering square, and how it was a shame that Pi-Holi wasn’t an MTG puzzle, since it could have been about the color pie. That led to talking about other games with colored wedges, and then we got the Trivial Pursuit a-ha. At this rate, I actually might print out the phrase list to refer to for extraction purposes.

I didn’t do too much after Hunt. It was mostly spent getting food with friends, complaining about the cold, and waiting in an airport for 12 hours. It turned out a bunch of Bay Area Hunters were waiting for the same flights, so it wasn’t as bad as it could have been. We talked about Hunt with other stranded passegners, and a few people from my team got dinner at Sbarro.

It felt obligatory.