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  Ando Meritee's Blog  
An introduction of Taraguchi rule2008-04-22 19:27:13
Many people who perhaps have not deeply been involved with new opening rule discussions, may wonder about what is the difference between simple 5-swap (also called "Tarannikov") rule and Taraguchi rule.

Taraguchi rule is practically same as simple 5-swap rule , but it has one extra rule, that allows black player to put five alternative 5th moves together with cancelling the white's right to swap after that.

The purpose of this article is to introduce this special additional rule, that makes "Tarannikov" rule turn into "Taraguchi".
To put the purpose of this additional rule condition in one sentence, the rule of allowing black player offer five 5th moves together with cancelling white's right to swap after that, is to avoid "crazy far-away" 4th move by white player.

Since the traditional renju shape is a compact shape, expanding slowly from the center, without any far-away moves during opening, it is important that the new opening rules would follow the same criterion. Furthermore, it is also important to keep the game fair for both sides, not giving one player too big "homework advantage".

Look at the example below:
alt="Your browser does not have Java installed. Please go to and press Download Free Java."
White player had just played a far-away 4th move. In simple 5-swap rule, black has now two choices:

1. to play own 5th move.
2. to swap (take white side, and let opponent play the 5th move)

Black player has never seen this 4th move, and the limited thinking time in clock does not allow him to make a proper judgment about which of the 5th moves is balanced enough so that he would not suffer from opponent's right to swap after that. So he will give up the choice (1), and will use choice (2) - to swap.

White player, having made a deep home analysis, makes a 5th move, also far-away. Maybe something like on the diagram below:
alt="Your browser does not have Java installed. Please go to and press Download Free Java."
Now the player is even more confused. He has a chance for final swap, but he cannot make a proper decision within his human abilities in limited time. As a result, he might make a mistake immediately and lose the game.

So, the opponent, having made a deep homework of the pair of "far-away 4th and 5th" moves, will have a big advantage.

Such situation will encourage gambling-style, because normally such far-away positions are sure win for one side, and the gambling player just hopes that the opponent makes a wrong judgment after the 5th move.

And such situation is not good for renju as a serious sport that would have more focus on actual skills and studies rather than getting lucky wins from extreme gambling positions.

Therefore, the rule "Taraguchi" was created. Black side has a right to play five 5th moves and cancel the white's right to swap after that, if the black player feels that the 4th move is too far and it is impossible to make proper judgment by human ability during limited time.

So, in Taraguchi rule, black is looking at the situation:
alt="Your browser does not have Java installed. Please go to and press Download Free Java."
Black player decides, the 4th move is unreasonably far, therefore, instead of using the traditional choices (1) play one 5th move, or (2) swap, he will use the choice (3) - to play five 5th moves on board and cancel white's right to swap after that.

He will place following stones (for example): h5, h6, h7, g8, h9. (maybe there are better choices but it is just an example anyway).

White has to choose one of the five choices and play own 6th move. It is a bitter situation for white, because all five choices are practically black win.

Therefore, white side must give up gambling style, and stop using those crazy far-away 4th moves in order to avoid sudden loss. And if white players a proper nearby 4th move, then black can already make a fair judgment about how to balance the game and the normal game can go on.

As you can see, the extra option of putting five 5th moves is more like a "warning against far-away style", and since nobody likes to commit suicide in game, nearly all games will be played with nearby 4th moves, therefore we will rarely see the five 5th moves actually appearing in the games.

So, the additional rule is just emphasizing the player discipline. As long as player plays properly, the extra option will not be used, so the actual actions of the game are just simple swaps during first five moves of the games, just as the simple 5-swap rule.

As mentioned in previous discussions before, a beginner can ignore the rights of swapping during the first 5 moves and study renju in a simple way during first months - just play turn by turn with his opponent and focus only on forbidden moves of renju. Playing this way, the player is still playing "in accordance with the real rule", because real rule allows the player to NOT swap, too, and the game would look the same.

The same way, the beginner can ignore the special feature of Taraguchi rule (putting five 5th moves), and just play normal turn-based game from the first move, until he becomes stronger and has more curiosity about additional features of the rule.
In conclusion, I just want to say that the article was written only to introduce the Taraguchi rule to those who have not been involved with rules study and know little about the differences of rules proposals. The example diagrams in my article are just illustrative and might not be fully correct in the concrete analytical viewpoint. The diagrams were just created to give a reader an imagination of a far-away move and the "headache" of making judgment after that.

Thank you for reading it. :)

P.S. Recently, the RIF is putting more focus on the 3-swap version of Taraguchi rule, excluding the rights to swap after the 1st and 2nd moves. The suggestion came from Japanese, as they think having less swaps will make the rule be closer to existing RIF rule.
About the Taraguchi name

Oh, and if some people wonder, where the rule name "Taraguchi" came from, then here is the story:

During World Championship 2005 in Tallinn, several players were discussing the new rules. At that time there were already several new rules, such as Yamaguchi, Sakata, Tarannikov.

Many people experimented with different rule variations during those days, trying to make new rules, or mixing the existing proposals. The Taraguchi rule was a kind of mixture of "Tarannikov" (many swaps) and Yamaguchi (many 5th moves).

Since the new mixed rule seemed interesting, it needed a nickname. Even though Rules Commission was trying to introduce the numbered names of opening proposals, it did not really became popular, as people still used the previous nicknames in their conversations.

So, the nickname was also needed for this new mix of two rules. Without any serious thoughts, there were just 2 candidates for names -  "Taraguchi" or "Yamannikov". :) The players decided that the first nickname was easier to remember, so it became an "offical nickname" from that day. :)

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