Irensei (囲連星)

[Samraku]

Rules

Japanese Rules (primary source)

Irensei is played on a 19x19 Go board, with Go stones, and Go capturing rules, and Go ko rules, but with one significant difference: the goal is not to surround territory, it is to get 7-in-a-row in the center 15x15 area (in other words, stones on the first and second line can’t be used as part of a 7-in-a-row). A winning 7-in-a-row can be either orthogonal or diagonal, but it must be a straight unbroken line of friendly stones

To lessen the turn order advantage, Black and White have subtly different winning conditions:

1. Black must get exactly 7 stones in a row in order to win
   — If Black makes 8-in-a-row or more anywhere on the board (even on the first and second lines), this is called overlining and Black loses the game immediately
2. White must get at least 7 stones in a row in order to win
   — Even if White makes 8-in-a-row or more, it is not an overline and White does not lose the game. In fact, if at least 7 of the stones are in the central 15x15, White wins immediately

Suicide is forbidden, with the exception that a suicidal move which makes a winning 7-in-a-row is allowed, and wins the game

To all but perfectly balance the game as well as increase opening variety, Swap-2 and Swap-5 are available as Pie Rules

Proverbs

These are just some obvious ones to get started

As always, remember that proverbs always have exceptions, and are often formulated with brevity in mind. Explanations are given for each of these proverbs, but keep in mind that they may assume ideal conditions, and reading must take priority

• 6 is a win
  • 6-in-a-row makes miai to extend to 7-in-a-row
• 5 is sente
  • if ignored, 5-in-a-row can be extended to 6-in-a-row
• 4 orthogonally is sente
  • if ignored, 4-in-a-row can be extended with a 1-point-jump, which the opponent must cut, and you don’t want to be forced to cut a 1-point-jump
• hollow is filled
  • a hollow line (one which is missing 1 or more stones from the middle, but has stones on both ends) is often just as good as if it were filled

Where to Play

Abstract Play is where I recommend playing. You can accept an open challenge, make one of your own, join the ASTs, challenge players directly, or all of the above . All games are correspondence, so feel free to join in the fun without the stress of finding time to block out for a live game

I look forward to playing more Irensei with other OGFers

Customizing Stone Colors

As Go players, we all expect Black to play first and White second, and thankfully Abstract Play allows a large degree of color customization. Here is a short guide to making the stones Black and White:

Step by Step Intructions

Click on the options button in the upper right

Scroll down to the bottom and click on Manage Palettes

1. Type #000 (or another dark color you prefer) into the box, and click Add Colour
2. Type #fff (or another light color you prefer) into the box, and click Add Colour
3. Give the palette a descriptive name (“go-stones” in this example)
4. Click Add Palette
5. Scroll down and click Save Changes

Click on Manage Color Contexts

Select Light Mode or Dark Mode depending on which one you use (or you can set color contexts for both modes)

For Dark Mode, set Borders Around Most Pieces to #fff (or another light color you prefer)

You can also play around with the other settings here, if you like

Scroll down and click on Save Changes

For Light Mode, set Borders Around Most Pieces to #000 (or another dark color you prefer)

You can also play around with the other settings here, if you like

Scroll down and click on Save Changes

Exit back to the main site

Go to any game of Irensei (the one linked here, for example, but any will do)

At the bottom-right of the board, click on the option icon (the one on the far right that looks like a gear)

Set Choose Color Scheme to Custom, and select your custom palette from the dropdown

Set Where Would You Like These Colors Applied to For All Irensei Games

Scroll down and click on Save

Refresh the page

Congratulations! you should have Black and White stones now!

[JethOrensin]

This sounds very interesting indeed!! Thank you for sharing this

[Samraku]

Got a nice Solarized board using the Custom CSS feature

CSS Code

/*
 * Site-specific
 */

:root[color-mode = "dark"] {
	body {
		background-color: #002b36; /* DM default background */
	}
}

:root[color-mode = "light"] {
	body {
		background-color: #fdf6e3; /* LM default background */
	}
}

/*
 * Game-specific
 */

/* remove shaded gutter */
g#gridlines polygon {
	opacity: 0;
}

/* insert demarcatation on the 3rd line*/
g#gridlines *[x1 = "100"] {
	stroke-width: 2;
}
g#gridlines *[x1 = "800"] {
	stroke-width: 2;
}
g#gridlines *[y1 = "100"] {
	stroke-width: 2;
}
g#gridlines *[y1 = "800"] {
	stroke-width: 2;
}

/* enlarge hoshi */
g#gridlines circle {
	r: 6;
}

Solarized RGB Values

Solarized Values

Background

base03: #002b36; (DM default)
base02: #073642; (DM highlights)

Content

base01: #586e75; (DM secondary; LM emphasized)
base00: #657b83; (LM primary)
base0: #839496; (DM primary)
base1: #93a1a1; (DM emphasized; LM secondary)

Background

base2: #eee8d5; (LM highlights)
base3: #fdf6e3; (LM default)

Accents

yellow: #b58900;
orange: #cb4b16;
red: #dc322f;
magenta: #d33682;
violet: #6c71c4;
blue: #268bd2;
cyan: #2aa198;
green: #859900;

Color Contexts

• Board Background: default background
• Gridlines and Most Other Lines: secondary content
• Borders Around Most Pieces: secondary content
• Fills, Like Blocked Cells and Some Glyphs: primary content
• Board Labels: secondary content
• Annotations, Like Movement Arrows: emphasized content

Palettes

Solarized Default

• Player 1: red
• Player 2: blue
• Player 3: green
• Player 4: yellow
• Player 5: violet
• Player 6: orange
• Player 7: cyan
• Player 8: magenta
• Player 9: emphasized content

Solarized Bicolor

• Player 1: base02
• Player 2: base2

[Samraku]

I’ve been playing more, and I think I’ve thought of a good phrasing for a proverb I wanted to include originally but couldn’t quite put into words: “liberties are life”. It means that it does not take many liberties before filling them would give you enough time to win, and thus filling them is too slow, and thus the stones are alive

[ArdillaRoja]

Have just started playing this too (including some interesting tussles with Samraku!) and really enjoying.

Go knowledge definitely transfers to some extent but different objective gives it a very different feel.

Because it’s a race (and there’s no territory or capture points to worry about) you don’t need to be as careful about keeping stones safe. It seems to be usually a waste of time to capture stones (unless they’re part of a soon-to-be winning line). So you end up with loads of scrappy aji everywhere that sometimes becomes helpful again unexpectedly.

I’m hoping I might get some skills transfer back to Go as well but we’ll see. (I played quite a lot of Blooms, a hex-based abstract that has a lot of overlap with Go, and found it changed my Go thought processes a bit).

[Samraku]

Updated css code to move the hoshi inward as for Gomoku, since play centers around the 15x15 central area, not the entire 19x19 board

Screenshots

CSS Code

/*
 * Site-specific
 */

:root[color-mode = "dark"] {
	body {
		background-color: #002b36; /* DM default background */
	}
}

:root[color-mode = "light"] {
	body {
		background-color: #fdf6e3; /* LM default background */
	}
}

/*
 * Game-specific
 */

/* remove shaded gutter */
g#gridlines polygon {
	opacity: 0;
}

/* insert demarcatation on the 3rd line*/
g#gridlines *[x1 = "100"] {
	stroke-width: 3;
}
g#gridlines *[x1 = "800"] {
	stroke-width: 3;
	x:T
}
g#gridlines *[y1 = "100"] {
	stroke-width: 3;
}
g#gridlines *[y1 = "800"] {
	stroke-width: 3;
}

/* enlarge hoshi */
g#gridlines circle {
	r: 6;
}

/* gomoku-style hoshi */
g#gridlines *[cx = "150"][cy = "450"] {
	opacity: 0;
}
g#gridlines *[cx = "450"][cy = "750"] {
	opacity: 0;
}
g#gridlines *[cx = "750"][cy = "450"] {
	opacity: 0;
}
g#gridlines *[cx = "450"][cy = "150"] {
	opacity: 0;
}
g#gridlines *[cx = "150"][cy = "150"] {
	cx: 250;
	cy: 250;
}
g#gridlines *[cx = "750"][cy = "150"] {
	cx: 650;
	cy: 250;
}
g#gridlines *[cx = "750"][cy = "750"] {
	cx: 650;
	cy: 650;
}
g#gridlines *[cx = "150"][cy = "750"] {
	cx: 250;
	cy: 650;
}

[Samraku]

Updated css code to fix the 3rd-line demarcation

Note that the background color, the color of the lines and coordinates, and the colors of the stones have been modified with Custom Color Contexts and Custom Color Palettes as described above. The css in this post will still work regardless of whether or not you change various colors

CSS Code

/*
 * Game-specific
 */

/* remove shaded gutter */
g#gridlines polygon {
	opacity: 0%;
}

/* insert demarcatation on the 3rd line*/
g#gridlines *[y1 = "100"][y2 = "100"] {
	stroke-width: 3;
}
g#gridlines *[y1 = "800"][y2 = "800"] {
	stroke-width: 3;
}
g#gridlines *[x1 = "100"][x2 = "100"] {
	stroke-width: 3;
}
g#gridlines *[x1 = "800"][x2 = "800"] {
	stroke-width: 3;
}
/* remove extensions from the demarcatation */
g#gridlines *[y1 = "100"][y2 = "100"][x1 = "0"] {
	stroke-width: 1;
}
g#gridlines *[y1 = "100"][y2 = "100"][x1 = "50"] {
	stroke-width: 1;
}
g#gridlines *[y1 = "100"][y2 = "100"][x1 = "800"] {
	stroke-width: 1;
}
g#gridlines *[y1 = "100"][y2 = "100"][x1 = "850"] {
	stroke-width: 1;
}
g#gridlines *[y1 = "800"][y2 = "800"][x1 = "0"] {
	stroke-width: 1;
}
g#gridlines *[y1 = "800"][y2 = "800"][x1 = "50"] {
	stroke-width: 1;
}
g#gridlines *[y1 = "800"][y2 = "800"][x1 = "800"] {
	stroke-width: 1;
}
g#gridlines *[y1 = "800"][y2 = "800"][x1 = "850"] {
	stroke-width: 1;
}
g#gridlines *[x1 = "100"][x2 = "100"][y1 = "0"] {
	stroke-width: 1;
}
g#gridlines *[x1 = "100"][x2 = "100"][y1 = "50"] {
	stroke-width: 1;
}
g#gridlines *[x1 = "100"][x2 = "100"][y1 = "800"] {
	stroke-width: 1;
}
g#gridlines *[x1 = "100"][x2 = "100"][y1 = "850"] {
	stroke-width: 1;
}
g#gridlines *[x1 = "800"][x2 = "800"][y1 = "0"] {
	stroke-width: 1;
}
g#gridlines *[x1 = "800"][x2 = "800"][y1 = "50"] {
	stroke-width: 1;
}
g#gridlines *[x1 = "800"][x2 = "800"][y1 = "800"] {
	stroke-width: 1;
}
g#gridlines *[x1 = "800"][x2 = "800"][y1 = "850"] {
	stroke-width: 1;
}

/* enlarge hoshi */
g#gridlines circle {
	r: 6;
}

/* gomoku-style hoshi */
g#gridlines *[cx = "150"][cy = "450"] {
	opacity: 0%;
}
g#gridlines *[cx = "450"][cy = "750"] {
	opacity: 0%;
}
g#gridlines *[cx = "750"][cy = "450"] {
	opacity: 0%;
}
g#gridlines *[cx = "450"][cy = "150"] {
	opacity: 0%;
}
g#gridlines *[cx = "150"][cy = "150"] {
	cx: 250;
	cy: 250;
}
g#gridlines *[cx = "750"][cy = "150"] {
	cx: 650;
	cy: 250;
}
g#gridlines *[cx = "750"][cy = "750"] {
	cx: 650;
	cy: 650;
}
g#gridlines *[cx = "150"][cy = "750"] {
	cx: 250;
	cy: 650;
}

[Samraku]

Ladders in Irensei

Ladders can’t extend across the entire board as they can in Go, but they do have some subtleties specific to Irensei that do not occur in Go

Assumptions

• Black is laddering White
• Capturing the laddered stones is a win for Black
• Allowing the laddered stones 2+ liberties without an immediate win with the laddering stones is a win for White
• All other wins on the board are slower
  • 7-in-a-rows using the laddering or laddered stones are wins, but all other 7-in-a-rows are considered to be slower
• Ladder breakers are not considered (it is assumed readers are familiar with the concept from Go)
• Edge effect is not considered (it is assumed readers are familiar with the concept from Gomoku)

Basic Ladder

This is the basic ladder position with no surrounding stones or interference from the edge of the central 15x15 region

• Winning for Black
  • By Ladder Abandonment
    1. Black plays out the ladder until an open 5
    2. Black abandons the ladder to make an open 6
  • By Ladder Completion
    1. Black plays out the ladder until a 7-in-a-row

Detailed Diagrams

Defender Tail Ladder

This is the basic ladder position but with the defender having a friendly stone behind their laddered stone

• Winning for Black
  • By Ladder Abandonment
    1. Black plays out the ladder until an open 5
    2. Black abandons the ladder to make an open 6

Detailed Diagrams

Defender Double Tail Ladder

This is the basic ladder position but with the defender having two friendly stones behind their laddered stone

• Winning for White

Detailed Diagrams

[Samraku]

Game Review: @Samraku vs barkardes

I hope this catches the interest of some people who might be interested in playing (I have an open challenge on Abstract Play, and there’re also Abstract Play Automated Tournaments (AP equivalent of OGS ASTs) if you want a wider variety of opponents. The analysis is basic, but can hopefully serve as an introduction to some Irensei concepts and how they relate to Go and Gomoku, as well as give an idea of how games go

Review

Samraku was Slicer and proposed this Pie. I have been using this exclusively lately. The idea is that as Black you can play A or B to solidify your position and form a strong attack on the bottom and/or right side, while as White you can play at C to create miai at D or E and fight for the outside

Barkardes chose White and played to the outside at 2. Much like in Gomoku, having the outside means having more room with which to make threats, but only if you don’t give away a faster win on the inside, of course

Black descended with 3 to fix the elephant eye. Much like in Go, keeping strong shape seems to be an excellent scaffold from which to build towards win threats

White continues to play for the outside at 4. Much as in Gomoku, this is an aggressive move. White is preparing an outside attack on the premise that Black can’t make a win on the inside

Black hanes, White extends, Black pushes, and White hanes, creating a cutting point at A

I think Black could immediately cut at A if desired and attack on the right side, but Black pauses to form a hollow seven (a pair of like-colored stones on the same row, column, or diagonal such that they threaten to complete a 7-in-a-row by playing the points in between over the course of 1 or more moves) with 3. White must respond to this, but any move White tries will be way too close to Black thickness, and thus give Black more strength through attacking as it runs away

White chooses to cut the 1-point-jump with 2, and true to the proverb, Black gets very nice shape after descending with 5, connecting with 1, (throwing in a probe at 3), and finally connecting with 5

Black could continue in the lower left, such as by cutting at D, but 1 also seems fine. The idea is that White has 3 weak groups (A, B, and C), while Black only has 1 strong group, and group A owes moves

White exchanges 2 and 3 both for strength and to overline Black (Black no longer has a potential win threat with A if the 2 White stones are captured because if Black fills those, they will have 9-in-a-row and will lose the game by Overline)

The hane at 6 seems very aggressive to me, given how weak White’s group is and how strong Black is in the area, so Black cuts immediately with 1, making the right-side White group look very near to death. Generally in Irensei, if one makes a capture, it is enough to win locally

White decides to sacrifice the weak group at A in favor of an attack around B. This is very all-or-nothing as Black will certainly be able to win in the lower right now, given enough time, so White must find a faster win in the center

Black blocks one end of the horizontal threat with 1, which also strengthens their stones

White forms a hollow six with 2. This may just be a matter of style, but I would have favored a hollow seven at A, but as Black never took A themselves, it worked out

After White answers 3 with 4, they need 5 moves (A, B, D, D, 3) to win, while Black also needs 5 moves (C, C, C, C, 5), but it’s Black’s turn. It works just like a semeai in Go where since both players need the same number of moves to win, Black wins regardless of whose turn it is if both players just try to play out their own wins. So after 5, if White can’t find a delaying action, Black will win. Though overall it’s too late, as Black can always go back and play their own delaying action at B if White finds a delaying action, and the Black group at B seems really hard to pin down

White seems to recognize this and plays out a few moves of the sequence before resigning

[Samraku]

New Proverb: Inside is Big

It takes surprisingly little space in Irensei to make a win, so it is easy to underestimate the potential value of the inside. While in Gomoku forced wins aim at threes or fours at an intersecting angle to eachother, and to be sure that also exists in Irensei, Irensei also often allows one to make a win parallel to one’s first threat, thus forcing a win in an alley only 2 rows wide (with some space on the side for liberties, of course)

More generally, if one dances around the outside of the opponent trying to block everything, the opponent is likely to become much stronger than you, split you apart, and proceed to easily win with a myriad of threats which your stones are too discoordinated to match