Tag → board-games

[IOI 2014 Part 3] Games of Luck and Strategy and Really Weird Noises

Shamelessly getting unfinished business out of the way. Yup, that’s me.

Excursion Day 1. We traveled down to Yilan on a bus. I played guess-it with Paul.

I was quite surprised at myself for remembering this game, but I think it’s simple and little-known enough to be worth mentioning. Guess-it is a remarkably pure game of luck and bluffing from one of Martin Gardner’s columns, played with a small odd number of cards, e.g. the 13 cards of one poker suit. The cards are dealt evenly to players (who can look at them) with one card left over, which is kept face down; players take turns choosing one of two actions:
  1. Name a card and ask the other player if he or she has it. These questions must be answered honestly.
  2. Guess the left-over card. The guesser wins if correct; the other player wins if not.

Guess-it is not trivial because sometimes you should ask the other player if he or she has a card that you already see in your hand; otherwise whenever you answered “no” to a query you’d immediately guess that the asked card is the hidden one. It is actually a solved game in the sense that the probabilities of the Nash equilibrium strategy for when to guess and when to bluff have been worked out already, but they’re not simple probabilities by any means and humans are terrible randomizers anyway. A few rounds of it sure beats rock-paper-scissors. I was very amused to lose almost all our games with 11 cards but win almost all of our games with 13.

Okay, no more gratuitous narrative excursions into game-theory. The first stop, National Center for Traditional Arts, was a very laid-back culture place with old-fashioned retro shops and streets.

[IMO 2012 Part 2] The Hotel of Deception

We finally arrived at the hotel at 3:30, meeting another local from Taiwan, Mr. Chen, who helped us carry some of our stuff off the bus. Po-Chiang, our guide, was waiting inside. We took more pictures and finally lugged the meager stuff we had off to our hotel rooms.

At least, we tried. I started to realize that there was much more to this hotel than it seemed.

Firstly, of course, was the confusing placement of rooms with numbers starting with 4 and 5 on the fourth floor (which would be the fifth floor by our numbering system, where the lobby is floor 1; but here the lobby was assigned 0. Off-by-one errors just waiting to happen here.) Secondly were the completely indecipherable signs. I don’t remember the details, but the first signs we saw read something like “560 ~ 540: left; 520 ~ 540: right”. Occasionally there would be weird slashes or half-slashes between the numbers instead (later I finally realized they were slanted, Comic-Sans-style capital Ys, or “and” in Spanish). Are these closed, open, or half-open intervals? And why the heck are their upper and lower bounds in a different order!?

We wandered through the corridors, peeking down each one, trying to figure out whether the numbers were increasing or decreasing and whether a parity argument (for those of you not fluent in math lingo, that means odds and evens) allowed for the existence of our room. Who knew the simple act of finding one’s living quarters could be so mathematically tasking? In the end, our rooms were in the last corridor, just about diametrically opposite to the elevators on the half of our floor. Oh well.

The room was pretty nice overall. The furniture and basic facilities were quite complete, with a sparkly bathroom and a couple tables and chairs of various shapes. The closet was big and had a safe, which was rather important because just about everybody we had met had warned us over and over again about all the incredibly skilled thieves, muggers, and pickpockets in Argentina. It was probably much safer (no pun intended) in the hotel, but with all of these warnings (later we would even find a notice from the hotel warning us to lock our doors) I was never entirely certain. There were lots of lights controlled by a set of confusing switches on either side of our beds. There was at least one white immovable divider cunningly disguised as a switch, one switch that didn’t ever seem to do anything, and one that turned everything off. The last one made a little sense after a while because it had pictures of stars and a moon on it, but the whole setup was still pretty non-user-friendly in my opinion. The awesome part was that our room was connected with the one next door with a tiny midway corridor, so by keeping the connecting doors unlocked, the four of us (me, WL, CPT, KYL) could share one room key and just hang out really conveniently. The other two had a room connected to one with two guys from Cyprus. I don’t think they interacted that much, although I know we got an inequality from them one of the days before the contest. We observed that Jensen didn’t work on it and didn’t really touch it afterwards, still living under the mistaken and highly deluded assumption that there was no way the PSC would choose an inequality now that they finally realized that everybody knew Muirhead.