Bill Gates and Petals Around the Rose (2003) | Hacker News Reader

Bill Gates and Petals Around the Rose (2003)

borrett.id.au

59 pointsRKoutnik26 comments

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If you want a game where the secret is different each time, you should try Eleusis:

http://matuszek.org/eleusis1.html

http://matuszek.org/eleusis2.html

If you try it, this tip is really important: "Remember that rules are always much harder than you expect them to be."

And that principle applies to Petals around the Rose too.

really? I found the rule for petals around the rose surprisingly simple (not to find it but once you know it)

The tip is for the person coming up with the rule--even rules that seem very simple will be harder to figure out than you expect.

Petals Around the Rose is a fun game to bring out at techie gatherings, as many people have not heard of it. A few years ago I was visiting some friends at Startup Chile, and I decided to entertain four other people with this game. They were all highly intelligent, though the only one to not solve the problem is also the most successful among them. Go figure.

Interesting puzzle. I had to look up why the name was significant. The algorithm seemed pretty clear after a few rolls. Upon looking up the puzzle, I found I had a different algorithm than the one presented as a solution on wikipedia that resulted in the same output.

Edit: Which made the post's conclusion strange to me, if the name is not required to understanding the problem, why should Bill's interpretation be so surprising?

Edit2: Do people have other good examples of puzzles like this? I'm aware of Zendo [1] which is a similar inductive reasoning game.

[1] https://en.wikipedia.org/wiki/Zendo_%28game%29

The name isn't required, of course. It's just a clue.

It arguably feels like a bigger accomplishment to deduce it from the clue. Kind of like a riddle.

Not exactly a puzzle, but a good game of Mao is always a fun challenge.

I'm curious what algorithm you came up with that yields the same outputs but isn't effectively the same. I could probably create a formula that doesn't directly reveal the key, but it would really just be an obfuscation of the real rule.

Edit: Actually, I see one other interpretation that relies on bqq if rira (minor spoiler). I guess if you arrive at this first, the name seems irrelevant.

Edit2: Rot13 for minor spoiler

Gur fhz bs gur frg bs bqq qvpr, zvahf gur pbhag bs bqq qvpr.

I played a similar game with some folks once, but I don't know the game's name. The person who knew the rule(s) explained that there was a planet that was like Earth, but it only had a subset of the things that Earth had. We guessed different things on Earth, and the teacher would tell us whether or not this other planet had them.

Some samples include: Planet has apples, green grass, trees, runners, and cheese pizza. Planet does not have bananas, plants, people, hamburgers, cats, dogs, houses.

I won't put the rule(s) here in case people want to try it.

Planet has summer but not winter, and fall but but not spring, right?

Yup! I remember my eighteen-year old self being pleased with "Planet does not have Audi, but it does have Audi TTs!"

Looking at it again, I think the game works better spoken than written out like this.

Probably so. Written makes it a lot more obvious.

Not exactly the same premise, but I've heard it called "Queen Anne Likes".

I know it as "In a Cool World..."

As in, "In a cool world, there is jelly but no bread", and, "In a cool world, we go skiing, but never snowboard."

I learned this as the Green Glass Door. Everything in the title is also valid to go through the green glass door.

https://en.wikipedia.org/wiki/Eleusis_(card_game)

Found it in one of the Martin Gardner books.

Various rules I've found online:

https://boardgamegeek.com/boardgame/5217/eleusis

http://howell.seattle.wa.us/games/rules/Eleusis.html

http://www.bicyclecards.ca/game-rules/eleusis/189.php?page_i...

http://www.nhn.ou.edu/~kieran/eleusis.pdf

The rules vary, and all these seem different than what I read in Martin Gardner's article. A quick and easy version of it can be played with a single deck, sheet of paper (to record the rules) and 3+ participants (dealer + at least 2 players, more is better, too many needs more decks).

Wikipedia has a (short) list https://en.wikipedia.org/wiki/List_of_games_with_concealed_r...

I quickly hit on the correct theory based on the name of the game, but dismissed it, because the secret rule does not correctly match the name. The problem is pointed out on Wikipedia [1].

[1] https://en.wikipedia.org/wiki/Talk:Petals_Around_the_Rose#DE...

Jr bayl pner nobhg gur crgnyf .Lur fvatyr cvc bs n bar vf n ebfr jvgu ab crgnyf, guhf pbhagf nf mreb.

that's all well and good, but why rot13 your post?

nm, for spoilers. Makes sense.

What defect is that supposed to introduce?

If you get a different result when you ignore the 1-face dice on a roll compared to when you don't ignore them, then the algorithm as you understand it doesn't match the algorithm that's the key to the game. In other words, you misunderstand how the solution works and haven't actually figured it out.

I rewrote this section to hopefully be clearer, but carussell is correct that if you think the secret rule doesn't match the name then you don't understand the secret rule.

Also, Wikipedia is a wiki. Anyone could have made this edit. I don't understand why people take the time to write on the Talk page about noncontroversial fixes but then leave the article untouched.

I think you and the anonymous Wikipedia user have both missed the point. The rot13'd comment in reply to your's covers it.

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