HexWiki - User contributions [en]

Tournaments

2011-08-01T14:15:45Z

Twixter: added Ludoteka weekly tournament

==Weekly real time Hex tournament on Ludoteka==
This is a free tournament on an 11x11 grid with a one minute time control.
See [http://www.boardgamegeek.com/thread/680832/weekly-colmena-automated-real-time-hex-tournaments here] for details.

==Online Hex tournament for Human players at Boardspace.net starts Jan 1,2011==
Individual games will be played in real time, but matches will be scheduled by
opponents at an agreed date and time.
More info [http://boardspace.net/cgi-bin/tournament-signup.cgi?tournamentid=23].

==First HEXX6 Tournament in Tiel, The Netherlands at June 6th 2010==

'''Hex, Y, HavannaH, Unlur, Atoll and Pünct'''
More info [http://www.hexboard.com/Tournament.htm here].

==International Tournament 2009 in Granollers (Spain) 2009==

More info [http://www.littlegolem.net/jsp/forum/topic2.jsp?forum=50&topic=353 here].

==Second Spanish Hex 13x13 Online Championship in Little Golem==

The Second Spanish Championship has just started!. More info at [http://spainhex.blogspot.com/ its blog].

== 8th Mind Sports Olympiad in Prague ==

The event will be held from September 27th to October 5th in Prague.
[http://www.deskohrani.cz/cgi/mso/index.pl?telo=propozice.pl&text=uvod.htm&turnaj=oly&hra=hxx&jazyk=en&rok=2008 Hex] might be played depending on the number of participants:

==Spanish Hex 13x13 Online Championship in Little Golem==

The first Spanish Championship started in January 2008, and it was played in [[Little Golem]] in a Round Robin (divided in groups). The winner was [[José María Grau Ribas]], [[user:Gregorio|Gregorio Morales]] finished second while José Ignacio Úbeda ended third. More info at [http://spainhex.blogspot.com/ its blog].

==International Tournament 2006 in Oslo==

Took place on August 11th - 13th 2006. Photos and results can be found on [http://www.littlegolem.net/jsp/forum/topic2.jsp?forum=50&topic=244 littlegolem].

==International Tournament 2005 in Wrocław==

The first international Hex tournament was held in May 2005 in Wrocław, [[Poland]].

Here is some information:
* a [http://masak.org/carl/wroclaw/ blog with results]
* a page with [http://www.photos-wroclaw.prv.pl/ photos from the event]

==Online Team Tournament in 2003==

[[Team Tournament 1]]

==See also==
[[ICGA]]

[[category: hex community]]
[[category: History]]

Talk:HexGui

2011-03-21T21:41:56Z

Twixter: Asking about Hex and Twixt for Linux

== HexGui and TwixtGui for Linux? ==

Is source code available? I run Gnome on Debian 6.0 for amd64.

Thanks for any info.--[[User:Twixter|David]] 22:41, 21 March 2011 (CET)

Handicap

2006-10-08T15:10:28Z

Twixter: /* Non-rhombic board */ informal proof that rhomboid grids do not work

Playing with '''handicap''' means to give one of the [[player]]s (preferably the weaker one) an advantage at the start of the game. The point of this is to make the game more even, so that it will be challenging for both players.

In [[Hex]] there is no standard way of playing with handicap, and because of this it is not very common to do so. This ought to be changed.

There are several ways a handicap could be implemented.

== Non-rhombic board ==
One natural way is to play with an ''m × n'' [[board]] where ''m'' is distinct from ''n'', and let the weaker player have the shortest distance between his sides. Unfortunately, this doesn't work very well, since there exists an easy, explicit winning strategy for the player with shortest distance.

[[Image:Rhomboid.png]]

Here is the winning strategy. Suppose the board is an m by m+1 grid. The diagram shows m=4. The board can be partitioned into two triangular regions of m cells on each side. Now pair each cell in one triangle with a cell in the other triangle, as shown. The pairing is like a mirror image which is shifted slightly. The winning strategy for black is to answer each white move by playing in the corresponding cell in the other triangular region. If black has already occupied the corresponding cell, then it does not matter where black plays.

Suppose the board is filled with stones, and white has a win despite the fact that black followed this strategy. That implies the winning white path must cross the red line at least once. Consider the highest point at which the winning white path crosses the red line. This crossing cannot occur between two white stones on the same horizontal row, since for each such pair of cells, black must have occupied one of them. That implies the crossing from left to right must "go down" from B to A' or C to B' etc. Let us call this pair of cells Y (on the left side of the red line) and X' on the right side. The corresponding cell to Y we will call Y'.

For white to have a winning path which crosses at this point, there must be a continuous chain of white stones from cell Y to the left white border row. But since black followed the above strategy, this implies there is a continuous chain of corresponding black stones from Y' down to the bottom black border row. Therefore the white chain is blocked from connecting to the right. This contradicts the assumption that white has a win, so black must have a win.

For other shape grids, m by m+k where k>1, the same strategy can be used, as long as the two triangular regions are adjacent to each other. For cells which lie outside these regions on the left or right, it does not matter how black responds to any white moves in these regions.
--[[User:Twixter|David]] 17:10, 8 Oct 2006 (CEST)

== Start with pieces on the board ==
Alternatively one can use the kind of handicap used in [[Go]]: The weaker player places a certain number of [[pieces]] on the board as his [[first move]]. A 1-piece handicap is the same as playing ordinary Hex without the [[swap option]]. With a handicap of two or more pieces, the first player either places the stones as he likes, or according to some pre-defined rules.

The drawback of this option is that even a 1-piece handicap gives a very big [[advantage]]. At least this is true on [[Small boards|smaller boards]] (such as the 10 × 10 board). On larger boards, such as 19 × 19 this may be a good solution, and weak players may even be allowed to place three or four pieces against the strongest players.

Handicap

2006-10-08T15:06:57Z

Twixter: /* Non-rhombic board */ informal proof that rhomboid grids do not work

Playing with '''handicap''' means to give one of the [[player]]s (preferably the weaker one) an advantage at the start of the game. The point of this is to make the game more even, so that it will be challenging for both players.

In [[Hex]] there is no standard way of playing with handicap, and because of this it is not very common to do so. This ought to be changed.

There are several ways a handicap could be implemented.

== Non-rhombic board ==
One natural way is to play with an ''m × n'' [[board]] where ''m'' is distinct from ''n'', and let the weaker player have the shortest distance between his sides. Unfortunately, this doesn't work very well, since there exists an easy, explicit winning strategy for the player with shortest distance.

[[Image:Rhomboid.png]]

Here is the winning strategy. Suppose the board is an m by m+1 grid. The diagram shows m=4. The board can be partitioned into two triangular regions of m cells on each side. Now pair each cell in one triangle with a cell in the other triangle, as shown. The pairing is like a mirror image which is shifted slightly. The winning strategy for black is to answer each white move by playing in the corresponding cell in the other triangular region. If black has already occupied the corresponding cell, then it does not matter where black plays.

Suppose the board is filled with stones, and white has a win despite the fact that black followed this strategy. That implies the winning white path must cross the red line at least once. Consider the highest point at which the winning white path crosses the red line. This crossing cannot occur between two white stones on the same horizontal row, since for each such pair of cells, black must have occupied one of them. That implies the crossing from left to right must "go down" from B to A' or C to B' etc. Let us call this pair of cells Y (on the left side of the red line) and X' on the right side. The corresponding cell to Y we will call Y'.

For white to have a winning path which crosses at this point, there must be a continuous chain of white stones from cell Y to the left white border row. But since black followed the above strategy, this implies there is a continuous chain of corresponding black stones from Y' down to the bottom black border row. Therefore the white chain is blocked from connecting to the right. This contradicts the assumption that white has a win, so black must have a win.

For other shape grids, m by m+k where k>1, the same strategy can be used, as long as the two triangular regions are adjacent to each other. For cells which lie outside these regions on the left or right, it does not matter how black responds to any white moves in these regions.

== Start with pieces on the board ==
Alternatively one can use the kind of handicap used in [[Go]]: The weaker player places a certain number of [[pieces]] on the board as his [[first move]]. A 1-piece handicap is the same as playing ordinary Hex without the [[swap option]]. With a handicap of two or more pieces, the first player either places the stones as he likes, or according to some pre-defined rules.

The drawback of this option is that even a 1-piece handicap gives a very big [[advantage]]. At least this is true on [[Small boards|smaller boards]] (such as the 10 × 10 board). On larger boards, such as 19 × 19 this may be a good solution, and weak players may even be allowed to place three or four pieces against the strongest players.

File:Rhomboid.png

2006-10-08T15:02:03Z

Twixter: diagram illustrating the unfeasiblity of row handicapping

diagram illustrating the unfeasiblity of row handicapping

File:Hexposition02.jpg

2005-02-15T14:55:35Z

Twixter: POV-Ray generated image, using modified source code for a Go board. The position is from Little Golem game 247486.

POV-Ray generated image, using modified source code for a Go board. The position is from Little Golem game 247486.