The extended Yusui rules

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11 posts in this thread

Yuriy Tarannikov
#1 2009-09-09 17:30:08

In this article I want to analyze the current situation with opening rules and to propose the new opening rules.

At GA RIF 2008 some new opening rules were certified and it was decided that WC from 2009 till 2012 will be played by Yamaguchi rules. After this different tournaments started to use different certified opening rules, a lot of interesting games in new variants were played. Nevertheless, there exists the problem: what to do after 2012? The GA RIF 2012 must decide it but if it will not be any decision at RIF GA 2012 (because of the absence of a majority or because of a veto) then the RIF opening rules will be returned to WC and a situation will become even worse since the players will lose at WC a lot of already tried variants.

The Yamaguchi opening rules gave some set of new variants. The main visible disadvantage of Yamaguchi rules is a huge difference in the number of possible 5-move positions in different openings. For example, it is possible to play d2 or i2 with 7 5th moves, i4 with 5 or 6 5th moves, after it there exist a lot of 4th moves. So, 50-100 positions after the 5th move are possible in i2, d2, i4. At the same time in some openings (like d11, i1) only 1-2 positions after the 5th move are possible. It is impossible to play i13 at all. Also, the problem to escape from boring draw variants in d11 was not solved. At WC 2009 nobody of players played d11 regularly but it did not solve the problem that such player can appear.

At the same time the well-known argument of Japanese against Soosyrv or Taraguchi rules is that the player number two can escape from some theoretical variants. So, an ignorance champion can appear.

Japanese proposed the Yusui opening rules. These rules are described here:

Yusui opening rules increase slightly the number of playable variants. At the same time its keep the main disadvantage of Yamaguchi rules. The difference in the number of variants between different openings is huge. It is possible to play i13 with only 1 5th move whereas it is possible to play d2/i2 already with 8 5th moves. The problem to escape from d11 becomes even worse. If in RIF or Yamaguchi rules the second player could transfer d11(2) into i10 or d7, in Yusui rules it is possible to do it only with one 5th move.

Next, I want to propose the extension of Yusui rules and explain its advantages.


Before the start of a tournament or a single game the number NMAX is established.

The player number one puts one of 26 openings and declares the number of 5th alternative moves. This number can not exceed NMAX.

After this the player number two has two possibilities:
(1) to decrease the number of alternative moves (if this number is not 1);
(2) to say: play.

If at some step some player decreased the number of alternative moves then his opponent has two possibilities:
(1) to decrease the number of alternative moves (if the current number is not 1);
(2) to say: play.

If at some step a player A said play then

his opponent the player B plays the 4th move;

the player A chooses the color of stones;

black player puts the currently declared number of 5th moves;

white player choose one of them;

white player plays the 6th move;

the game continues by regular Renju rules.


Remark. At WC 2009 in some games 7 5th moves were declared. Therefore, at high-level tournaments it is not reasonable to establish NMAX smaller than 7, opposite we will lose some already played variants. So, it is reasonably initially to put NMAX=7.

Remark: to indicate the action play it is convenient to put a white stone at an edge of a board.



The player number 1 puts i8 and declares 6 5th moves.


The player number 2 decreases the number of 5th movers to 5.

The player number 1 decreases the number of 5th movers to 3.

The player number 2 says; play.

The player number 1 plays 4-h9.


The player number 2 chooses the color.

Black player puts 3 5th moves.

White player choose one of them.

White player plays the 6th move

The game continues by regular Renju rules.


I) THE PLAYER NUMBER 2 CAN NOT ESCAPE FROM CLASSIC THEORY since the player number 1 can put an opening and declare the minimal number of 5th moves possible for this opening or even smaller.



The player number 1 puts i12 and declares 2 5th moves. If the player number 2 will decrease 2 to 1 then he will have a big disadvantage. So, the player number 2 is forced to say: play.

The player number 1 plays 4-g9.


The player number 2 chooses black stones.

The player number 1 tests the knowledge of the player number 1 in this variant.





The (crazy) player number 1 puts i13 and declares 7 5th moves.


The (conservative) player number 2 decreases the number of 5th moves to 1.

The player number 1 is forced to say: play.

The player number 2 plays 4-g9.


The player number 1 chooses the color.

Black player plays the 5th move.

They play a well-known variant.




The (crazy) player number 1 puts i13 and declares 7 5th moves.


The (crazy) player number 2 says: play.

The player number 1 plays 4-f10.


The player number 2 chooses the color.

Black player puts 7 5th moves.

They play a crazy variant and develop a new opening theory.



The next rule is only for high-level tournaments. If it is recognized that some opening leads to a boring sure-draw variant then for this opening in the tournament regulation it can be established the minimal number of alternative moves for the declaration at the first step. For example, if it is accepted that d11(2) leads to a boring sure-draw variant then in a tournament regulation will be established that it is possible to put d11 only declaring at least 3 5th alternative moves. It follows that any player can escape from d11(2). Indeed, he will not put d11 as the player number 1 and if he will be the player number 2 and the opponent will put d11 with at least 3 5th moves then he can say play immediately. At the same time if two players want to play d11(2) both then they can do it:



The player number 1 puts d11 and declares 4 5th moves.

The player number 2 decreases the number of 5th alternative moves to 2.

The player number 1 says: play.

The player number 2 plays 4-i10.


They play the standard variant of d11(2) by their mutual decision.

If during the following development of the opening theory it will be found that some other openings leads to a boring sure-draw variants then the minimal number of 5th moves for the first declaration can be established for these openings too.


For tournament of beginners it is possible to set NMAX=1 or NMAX=2.

If NMAX=1 then rules are very close to the rules without alternatives only the player number 1 puts 4 moves instead of 3.

If NMAX=2 then rules are quite close to classic RIF rules.

Please, write your comments about the extended Yusui rules.

Igor Magdeev [img_at
#2 2009-09-10 02:16:56

I have some questions :
- What are the benefits of NMAX being declared? It seems a role of NMAX to quantify the levels of tournament (from beginners to highest) only. It would be better to see NMAX role introduced in details.
Of course, I can imagine that we can deal with long "bidding stage" before actual stones appear on board in case of too many alternatives suggested at first. But it seems stupid for both players to do so.

- The NMIN value is questionable also. If we do declare it for certain opening only but not for all openings, then the rule is not "general". May be for quantifying the level of tournament it is better to use NMIN (=1 for beginners) for all openings instead of NMAX?

- The last point for beginners. How new rules will be pretty close to classic if the FIRST player will put 4 moves on board (second says "play")? What are the preferences to swap after 4th move but not after 3rd?

Yuriy Tarannikov
#3 2009-09-10 14:23:29

Igor, thank you for your interest and for your questions.

At first, I note that I did not create my own original opening rule. I just extended the rule proposed by Japanese. Different players or group of players (including nations) have different requirements for opening rules. Sometimes, creating own original rule it is difficult even to imagine a reason why others will not accept this rule. Therefore, my idea was to make minimal possible changing in a rule proposed by Japanese to satisfy requirements of European players. More significant changes have a risk that it will kill something important for creators of an original rule. In particular, in this case I try to extend the space of playable variants and to make it uniform along all 26 openings.

Concerning NMAX, if it will be allowed to declare 30 5th moves then in some situations it can be used by some players without a risk of an immediate loss. But it be estimated as very strange situation by many our opponents and a good rule can be declined only by this reason. Maybe, even 7 5th alternative moves are too much but here there exists an argument that 7 5th alternative moves were played already at WC (World Championship), so, if MNAX will be smaller than 7 then we will lose some variants already played at WC but we must try to keep all already played positions. For tournaments with only crazy participants it will possible to set NMAX=221 (although a standard renju set has not such many black stones).

"Bidding stage" it is a good analogy!

Concerning a non-general rule for NMIN in some openings, here we have contradictory requirements: by Japanese requirement the player number two can not escape from some specific theory whereas by European requirement a player must have possibility to escape from boring sure-draw variants. I do not see a general way to separate boring draw variants form all theory. It is the problem of a convention; it depends on current development of the theory and can be reconsidered. Note that in talk Japanese sometimes proposed to prohibit d11 at high level tournaments at all. In my proposition of Extended Yusui Rule any previously played position can appear in a game but maybe after some bidding steps. Maybe, after some time it will be possible to introduce the common NMIN for all openings but now we must be very careful to avoid the loss of variants.

Concerning the similarity of the rules for NMAX=2 to RIF rules, we have in most part of RIF openings the advantage of black. So, this advantage will not change after any 4th move. So, the procedure will change but the positions and real possibilities will be the same. Only in openings with an advantage of white (i13, d13, i1) the new possibilities will be a bit wider due to non-optimal 4th moves.

Yuriy Tarannikov
#4 2009-09-10 14:49:19

If NMAX=7 seems to be too high then it is possible to use the next system:

To set NMAX=4 or NMAX=5 but to allow to make the first declaration higher than NMAX. In the last case the game will be played by Yamaguchi rules. It allows to keep all variants already played at WC. After some period and an accumulating of some knowledge it will be possible to increase NMAX.

#5 2009-09-10 23:01:36

A very interesting suggestion. Probably, it goes in the right direction.

In example II), if a conservative player thinks, that the resulting position in 5i is unfavourable for black, than he should throw away his conservatism and get an idea of all 4th moves, relevant with respect to NMAX, in the 13i opening. The same, probably, in all other openings. So, an "ignorance champion" has really little chances.

By the way, what can a conservative player do in 13d?

The magnitude of NMAX is a matter of discussion. In such openings, like 2i or 4i, there a lot of quite reasonably looking 4th moves, which have at least 7 winning (big advantage) 5th moves. To my taste, NMAX=9 would be better.

Ofcause, the problem here is that only one number NMAX serves for the whole set of openings, which have a large dynamic range for the the number of 5th moves. This will require involving into consideration many new unfamiliar 4th moves in the openings, traditionally strong for white.
But maybe it's not that bad in itself.

Yuriy Tarannikov
#6 2009-09-11 00:02:29

Vladimir, thank you for your interest and for your opinion.

I think that the most conservative line in d13 is to declare 3 5th moves taking in a view the move 4-i9. Here two 5th moves give an advantage to black (5-i7 and 5-j9) and two 5th moves go to well known *almost* equal positions: 5-i8 (shifted d12=i12) and 5-h6 (transfer into i10). But a conservative player must be ready that the opponent will declare 1, 2 or 3 5th moves wishing to play 4-i10, 4-g10, 4-f7 or 4-g7. Of course, a conservative player knows the moves 4-g8 and 4-g9.

#7 2009-09-14 02:26:23

I don`t think that NMAX is so important because I can`t see future for yamaguchi rule anyway. Because the WC already showed that there ain`t many variations that are interesting or even possible to play.

But what about changing Taraguchi from 5swaps to 6 swaps(or even7?) ? And the five 5th move rule also to seven 5th moves. With 6swaps it would be silly to put crazy 4th move because you should put 5th and 6th moves also and good players would find a good plan after 6th moves anyway.

Yuriy Tarannikov
#8 2009-09-14 03:35:18

Andry, thank you for your comment. It is not a problem to create a new opening rule. The hard problem is to accept good rules for WC after 2009 since there exist contradictory approaches.

By the way, could you estimate the next 6-move position?

Yuriy Tarannikov
#9 2009-09-14 03:59:16

Let me try to make some moves:

#10 2009-09-14 06:04:23

yeah I gues it would be too "crazy". Maybe creative players could put 5th and 6th move themselves after such 4th move but maybe not the best solution. Still it would be interesting to play test games with such rules.

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