Hex
Hex is a beautiful and elegant game first invented by Danish mathematician Piet Hein in 1942, who called it "CON-TAC-TIX." It was independently invented by famous mathematician John Nash (subject of A Beautiful Mind) when he was a graduate student at Princeton in 1948. It was called Nash, or sometimes John (because it was sometimes played on bathroom tiles.) In 1952 Parker Brothers marketed it under the name of Hex, and the name stuck.
Hex is admired by many Go players (or so I'm told). It is played on an NxN rhombus of hexagons, where both players pick two opposite sides each take turns putting stones down on the board to try to form a solid connected bridge to opposite sides. The size of the board varies, according to circumstances:
- 5x5 and 7x7 are often used for educational purposes.
- 10x10 is popular on some sites, particularly for blitz tournaments.
- 11x11 is the most popular size, and the one recommended by Piet Hein.
- 13x13 is the common tournament size.
- 14x14 is used at some sites, and was the one recommended by John Nash.
- 15x15 to 19x19 games are offered on some sites, but are not often played, since they are so time-consuming.
This is what it looks like:
The only way to block your opponent from making such a bridge is to make your own. Hex thus has the unusual property that winning the game is exactly the same as not losing it. This is a very useful concept in Hex strategy since if you unconditionally block your opponent from winning the game, you've won the game yourself.
Having the first move confers an important advantage. Hex players typically use the Swap Rule, sometimes called the Pie Rule, to make the game more even.
Hex compared to Go
- Go and Hex have similar branching factors at similar sized boards, but Hex games are usually shorter, especially at lower levels.
- Both games have territorial and connection aspects, but in opposite amounts.
- Both games have immobile pieces, which is thought to give humans an advantage over computers. However, since Hex pieces are never removed, Hex positions are easier to analyse logically. The strongest Hex programs exploits this, using an approach similar to theorem-provers.
- In Hex, it is always better to have a stone of your colour on a point than nothing. This is not the case in Go, and makes Go harder to analyse.
- Because of the connection aspect of Go, the games have many similar tactical concepts such as ladders, ladder breakers (called ladder escapes in Hex) and joseki (called edge templates in Hex).
- Because pieces are never removed, Hex is a finite game without needing a superko rule.
- Hex does not have an official handicap system. However, handicaps are often handled by not using the swap rule, and instead place the first piece according to how large the handicap should be. Giving free moves at the start of the game is also sometimes used, but only when differences in level are very large.
Hex playing (online)
- Little Golem features Hex games over the web.
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http://www.boardspace.net/ Realtime play against real opponents.
and many other sites ...
Stategy
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http://www.abstractgamesmagazine.com/hex.html (Basic Strategy + some interesting puzzles) DEAD LINK
Wiki for the game Hex
http://www.hexwiki.org Hex Wiki
some interesting pages:
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http://www.hexwiki.org/index.php?title=History_of_Hex
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http://www.hexwiki.org/index.php?title=Board_size
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http://www.hexwiki.org/index.php?title=Draw
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http://www.hexwiki.org/index.php?title=Hex_theory
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http://www.hexwiki.org/index.php?title=Strategy
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http://www.hexwiki.org/index.php?title=Puzzles
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http://www.hexwiki.org/index.php?title=Computer_Hex
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http://www.hexwiki.org/index.php?title=Special:Allpages
Perfect Play
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http://www.mazeworks.com/hex7/ hex playing applet
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http://www-2.cs.cmu.edu/~hde/hex/hexfaq/ Hex IAQ (infreqently asked questions)
Computer Hex
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http://www.cs.ualberta.ca/~hayward/hex Wolve (winner computer olympiad 2008), MoHex (UCT algorithm)
- report Beijing 2008:
http://www.cs.ualberta.ca/~hayward/papers/rptBeijing.pdf
- report Beijing 2008:
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http://six.retes.hu/ Six, a Hex playing program for Linux/Un*x systems running KDE
- JHex (hexrecorder), see sourceforge
- HexGui (derived from GoGui); can attach Six-engine
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http://jhex.sourceforge.net/ small hex program, with weak computer opponent
- (
http://www.cs.newcastle.edu.au/~mihex/ MIHex: Machine Intelligence for Hex)
References
- The source for much of the above information was
http://www.cs.ualberta.ca/~javhar/hex/, a good site for those who wish to learn more about Hex. DEAD LINK
Links
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http://en.wikipedia.org/wiki/Hex_(game) (Wikipedia article)
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http://www.cs.unimaas.nl/icga/games/hex/ ICGA: Hex
See also
- Connection Games
- Havannah a game, similar to hex
- Twixt another connection game
- Gonnect A go variant: Go+Hex=Gonnect