iopq wrote:some moves that are not even eyes are considered points in this ruleset, and don't have to be made provided the automatic scoring is sufficiently good.
In practice, it will be quite difficult to write a logical ruleset that automatically distinguishes such "hidden" points. Most area scoring rulesets are written to count "stones + eyes" and they require explicit plays to fill in such empty points. Well, if the automatic scoring program is good enough, it may not be necessary, but I wouldn't trust the program and would keep playing unless I am 100% sure it works that way.
iopq wrote:When you agree to score and disagree on the amount of points, every move you make in this hypothetical play scenario is worth one point, you don't need to fill the dame to force the pass stones after you've agreed to score since it doesn't change the outcome of the game
I prefer that a ruleset recommends to finish a game by the agreement of both players, and "agreement" can in principle include all the points one should score. Of course, whenever they fail to agree, they must keep playing according to the ruleset. There is no harm in giving them a chance to make an agreement, rather than following a (sometimes) painful formal game ending procedure. (Who makes two or more passes in a real life game anyway?)
Re: Territory-style rules with a group tax
Posted: Sun Nov 29, 2020 7:20 am
by iopq
jaeup wrote:
iopq wrote:some moves that are not even eyes are considered points in this ruleset, and don't have to be made provided the automatic scoring is sufficiently good.
In practice, it will be quite difficult to write a logical ruleset that automatically distinguishes such "hidden" points. Most area scoring rulesets are written to count "stones + eyes" and they require explicit plays to fill in such empty points. Well, if the automatic scoring program is good enough, it may not be necessary, but I wouldn't trust the program and would keep playing unless I am 100% sure it works that way.
iopq wrote:When you agree to score and disagree on the amount of points, every move you make in this hypothetical play scenario is worth one point, you don't need to fill the dame to force the pass stones after you've agreed to score since it doesn't change the outcome of the game
I prefer that a ruleset recommends to finish a game by the agreement of both players, and "agreement" can in principle include all the points one should score. Of course, whenever they fail to agree, they must keep playing according to the ruleset. There is no harm in giving them a chance to make an agreement, rather than following a (sometimes) painful formal game ending procedure. (Who makes two or more passes in a real life game anyway?)
I mean the agreement can include "we will score the game as if we filled the dame, and then every player played prisoner exchange go by filling the points in seki and their own territory"
if you disagree who gets what point, the player who first asked to score gets to resume play and then you keep playing until you reach an agreement. At some point prisoners are exchanged and one player runs out of legal moves and prisoners. That player loses and there doesn't need to be an agreement. Even if he's trolling, he can't do anything once every group has only two liberties, even if he suicides, eventually that area of the board will be filled. At that point he has no prisoners or legal moves and he just automatically loses.
Re: Territory-style rules with a group tax
Posted: Sun Nov 29, 2020 11:35 am
by iopq
We can imagine the 6.5 komi as a Black pass stone on the side of the board and six in White's bowl.
$$B
$$ ---------
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . X 1 O . . . |
$$ | . . . X 2 O . . . |
$$ ---------
[go]$$B
$$ ---------
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . X 1 O . . . |
$$ | . . . X 2 O . . . |
$$ ---------[/go]
So White gets the last dame and Black should immediately throw the Black pass stone into White's bowl. This gives White 7 prisoners, 27-2=25 points of territory. Black has 34-2 points of territory, so after they all fill their respective territories it will be White's turn and Black wins.
$$B
$$ ---------
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . 3 . X O . . . |
$$ | . . . X 1 O . . . |
$$ | . . . X 2 O . . . |
$$ ---------
[go]$$B
$$ ---------
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . 3 . X O . . . |
$$ | . . . X 1 O . . . |
$$ | . . . X 2 O . . . |
$$ ---------[/go]
Black mistake, he starts filling his own territory before taking the pass stone. White throws the pass stone into Black's bowl taking his free pass instead. Now Black has to move and he lost a point of territory, having 31 points to White's now 6 prisoners and 25 points of territory. Because after White throws the passing stone back into the bowl it's Black's move, Black loses.
$$B
$$ ---------
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . X . X O . . . |
$$ | . . . X 1 O . . . |
$$ | . . . X O O . . . |
$$ ---------
[go]$$B
$$ ---------
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . . . X O . . . |
$$ | . . X . X O . . . |
$$ | . . . X 1 O . . . |
$$ | . . . X O O . . . |
$$ ---------[/go]
You can see the order of the moves was different in this game, so Black got the last dame. But the result is the same as the previous game, White gets to pass for free winning the game.
The result of this ruleset is the same as territory scoring with a group tax in this case.
Re: Territory-style rules with a group tax
Posted: Sat Dec 05, 2020 12:54 am
by iopq
I need some comments from rules experts on the forum.
Board and plays
1. A go board consists of intersecting curves.
Commentary: Most go boards use straight lines to form a flat grid. The most popular sizes consist of 9x9, 13x13, and 19x19 intersections.
2. A play occupies one intersection on the board that is currently not occupied with a certain color. Occupied points are called stones.
Commentary: The board usually has no stones at the beginning of a game, but can also be set up with existing stones to handicap a game or force variation. In this case, you can say that the colors were forced to make plays on certain intersections at the beginning of the game.
3. During the game, players take turns choosing an action for their color. This action can be making board plays, or choosing not to make a board play, called a pass.
Commentary: The most common number of players is two, but sometimes four players play two different colors, known as pair go. Another form of handicap is to force some of the colors to skip the first few turns to let the other players play a few stones, known as free handicap.
4. An intersection is said to be reaching another intersection if along one curve there exists no other intersection with a different curve between those two intersections.
Commentary: on a rectangular grid these are points that are horizontally or vertically adjacent to each other. There are two neighboring points when the intersection is a corner, three when it's on the side of the board, and four in the middle.
5. A group of stones is a set of unique stones. Any stone that reaches only empty points or stones of other colors is said to be a group of one stone. Any stone that reaches another stone of the same color is in the same group as that stone.
Commentary: A group is a set of stones of one color that are connected to each other. Being connected to each other means that any stone in the set can form a reaching path through the set to any other stone in the group.
6. A group is said to be reaching an intersection if any of its members reach that intersection. A group reaching a number of unoccupied intersections is said to have that number of liberties.
7. When one color makes a play on the board, other color stones that have zero liberties are removed from the board leaving the intersections empty in the same order as the order in which colors take turns, starting from the next color to play and finishing with the same color as the one that just played. This is called a capture.
Commentary: This means when the player plays a stone that is now in a group that has no liberties, he still has the chance to remove groups of other colors first that have no liberties. This ruleset also allows the player to remove stones of his own color by filling their own last liberty which is called multiple stone suicide.
8. A player is not allowed to recreate any previous board configuration at the end of their turn where all of the intersections were occupied by exactly the same colors at any previous point in the the same game.
Commentary: This prevents players from creating infinite cycles of play, known as a ko ban. It also prohibits single stone suicide as the the result. Passes do not remove ko bans since they do not alter the state of the board.
Scoring and prisoners
1. When a player's stones are captured, a number called the prisoner count of that color is increased by the amount of stones removed.
Commentary: The prisoner count doesn't have to start at zero. In a two player game, the first player might give up 7 prisoners at the start, while the second player gives up 0. The difference in the number of prisoners at the start of the game is called komi, in this case 7. There are other ways of handicapping a game, for example to give the weaker player the first move, and make the first player also give up more prisoners, called reverse komi indicating it's a negative komi value.
2. Each color can pass for free until they have made as many plays plus free passes as one of the other colors has made plays. After the number is equalized for all of the colors, no player can make free passes.
Commentary: Because colors all take turns in order, there can be a situation where the color who played the last beneficial move played more board plays than some other colors. In that case the remaining colors who didn't get to make as many moves can pass once to equalize without freeing prisoners.
In the case of a handicap, this lets the other colors pass at the end of the game to equalize the number of moves, since giving a handicap is considered letting the other colors make several actions in a row.
3. Further passing decreases every other color's prisoner count by one.
Commentary: The rule is formulated that way to accommodate more than two colors.
4. When a player's prisoner count drops below zero, that player can pass to finish the game. The players can then compare scores and the lowest prisoner count wins.
Commentary: Let's say Black moved first and White moved second and they have no prisoners. If White passed first, he doesn't have to free any prisoners. Then when Black passes, he has to free a White prisoner, making White's prisoner count -1, then White passes to end the game, making Black's prisoner count -1, which makes it a draw.
Second, if White takes the last free point, Black cannot pass for free, Black passes giving White -1 prisoners, White passes giving Black -1 prisoners also ending in a draw.
So the last shared point both players can take is not worth anything.
If you start Black off with a fractional number of prisoners like 6.5 to avoid draws. This is equivalent to giving 6 prisoners to White and declaring White wins all draws.
5. A color can concede the game avoid having to make further actions.
Commentary: in a two color game this results in a win for the other color.
6. Players can agree to count the game at any point they find convenient. If players disagree about the score, they can resume playing with the same player to move as before.
Commentary: once there's no difference in the order of the last few moves players can speed up the game by agreeing to count the result. Shared points that both players can take at any time do not count for anything since the order in which they are taken doesn't matter. The rule in which all players must make the same number of moves means that after filling those points, the next player to play should pass. That means that you can score the game without filling them since the result is the same. If the other player doesn't agree, you can resume from that point and keep playing. In other words, when players don't agree on the game result, they will eventually have to play passes as they run out of legal board plays, eventually ending the game.
Re: Territory-style rules with a group tax
Posted: Sat Jun 19, 2021 11:45 pm
by Yoav Yaffe
I think Ultimate Go (see https://senseis.xmp.net/?UltimateGo ) achieves exactly that - the "score" (which is not explicit in the rules) is the number of safe moves you can make, and yet there is sharpness, so for example a teire move is never completely free - it can turn a win into a draw (jigo), and a draw into a loss.
iopq wrote:I have just got this idea by reading that KataGo prefers not going into 3-3 point under a 4-4 stone with the group tax rules because of the 2 point penalty.
Could a very logical and simple territory-style ruleset be derived from the concept of "territory is the amount of excess moves you can make". How to make that into a consistent ruling?
Maybe after the game is considered finished and the play is hypothetical it should be something like this:
1. The side to move doesn't matter anymore, you can access the position from both sides when the side to move has one more move that's a dame.
2. When one side can make an unanswered move, that's a point (in other words, pay 1 stone per pass)
This difference game results in:
a. black first captures one stone (+1), white captures three stones (-3) and then black cannot continue to play without giving up more points (-1)
b. white first captures (-2) and black cannot continue to play (-1)
in other words it is worth 3 points for white in both cases
of course, if you LOSE more than one point by moving first you just pay the 1 point to pass instead
if neither side wants to move, the position is scored as worth nothing for both players (seki)
How would this ruleset work in other weird cases? My point is to have the SHARPNESS of territory counting (wins by 6 and 7 possible), the ability to leave dame on the board in online play, but also be able to judge the result of all finished boards, and allow for hypothetical resolution of life and death