Brandubh 7x7

Tafl rules
Draganov
Posts: 7
Joined: Fri Oct 30, 2020 2:59 pm

Re: Brandubh 7x7

Post by Draganov » Sat Nov 14, 2020 2:57 pm

What is the difference between Irish Brandubh 1 and Irish Brandubh 2? Can someone explains their rules and point out the differences. I found out the rules of Irish Brandubh 2 but the rules for Irish Brandubh 1 were only written in French language.

Auskor
Posts: 8
Joined: Sat Sep 19, 2020 9:36 am

Re: Brandubh 7x7

Post by Auskor » Wed Nov 18, 2020 11:30 pm

The rules for Brandubh 1 and Brandubh 2 are identical except for one detail - the capture of the king when it is next to the throne square.

In Brandubh 2 black only needs 2 pieces to capture the king - the same as anywhere else on the board.

In Brandubh 1 when the king is on the squares c4, d3, e4 or d5 then black needs three pieces to capture the king. For example if white king is on d3 black would need to have pieces on c3 and d2 before moving a third piece to e3 and capture the king.
Anywhere else on the board the king is captured by 2 pieces.

I believe Brandubh 2 was created as Brandubh 1 proved to overly favour the white player. The game balance stats. appear to show that Brandubh 2 is a better balanced game.

Draganov
Posts: 7
Joined: Fri Oct 30, 2020 2:59 pm

Re: Brandubh 7x7

Post by Draganov » Fri Nov 20, 2020 5:13 pm

Thank you, Auskor for the detailed explanation. I will definitely try these variants.

Hnefihunter
Posts: 2
Joined: Fri Apr 05, 2019 12:28 pm

Re: Brandubh 7x7

Post by Hnefihunter » Wed Jan 20, 2021 6:49 pm

Additional rule: If the king moves to d3, but the attackers are already on the sides: с3 and e3. In this case, the king can be captured by surrounding him on the 3rd side, viz. move to d2. In practice, however, this is rather rare.

Auskor
Posts: 8
Joined: Sat Sep 19, 2020 9:36 am

Re: Brandubh 7x7

Post by Auskor » Sun Jan 24, 2021 12:39 am

Hnefihunter, Just to be clear about your last comment - the 3 piece capture you mentioned is only valid in Brandubh 1

Unhandyandy and I played a Brandubh 2 game to test the very situation you described - see game in brandubh 2 archive 2020-9-22 Unhandyandy .v. Auskor where after playing the king to d3, between black pieces on c3 and e3 , we found that playing a black piece to d2 did not end the game. We agreed a draw after the move was played.

It appears there is no 3 piece capture in Brandubh 2 - it only exists in Brandubh 1. I guess that is why it is harder to win with white in Brandubh 2.

Hnefihunter
Posts: 2
Joined: Fri Apr 05, 2019 12:28 pm

Re: Brandubh 7x7

Post by Hnefihunter » Sun Jan 24, 2021 11:46 am

I don’t argue, maybe this move is not programmed by Aage.

Branan and I tested new modifications of the game. Capturing the king from both sides next to the throne is his idea. During testing, we encountered the situation I described. If the king gets between the attackers, there is a danger for the pieces. In this regard, I proposed the rule of three-way capture for Brandubh 2.

In my playing practice, I only got into such a situation once. I like Hagbard's expression: «The white piece is the active party, it is actively attempting to go somewhere. The black piece is just reacting to white's efforts. And so white is the desperate party who has to succeed in this effort or else lose if the efforts fail».

If this situation becomes a frequent annoying game-breaking phenomenon, I'll change my mind. For now, I suggest adhering to the rule.

Auskor
Posts: 8
Joined: Sat Sep 19, 2020 9:36 am

Re: Brandubh 7x7

Post by Auskor » Sun Jan 24, 2021 7:21 pm

Hnefihunter,

'I suggest adhering to the rule'

The point is that the 3 capture rule is not included in the current Brandubh 2 rules as posted on the site, nor is it programmed by Aage. I looked back at the posts in this forum topic - page 4 - and I think it is clear from the posts on 15 and 16 March 2020 of Hagbard and Branan that they agreed that the 3 piece capture is not included in Brandubh 2 rules.

I don't know the full history of what was tried when developing the Brandubh 2 rules - if you want the rule change I guess you need to contact Hagbard. I suppose it would be a way of helping the game balance towards black although I think that white's task is hard enough at the moment.

Abbas Agraphicus
Posts: 26
Joined: Mon Oct 12, 2020 9:05 am

Re: Brandubh 7x7

Post by Abbas Agraphicus » Mon Feb 08, 2021 11:48 am

Hi guys,
that rule was discussed in the past posts of the topic, and not included in the ruleset for BR2.

If I may say my humble opinion, I don't see the necessity of adding it, also because, especially in small board variants, even the slightest change can twist the balance a lot, and by now it seems to be quite good for a 7x7 game.

One thing that could be done is adding an example of that specific situation to the rules, with a board image, to clearly show that the king is not captured that way. It could avoid the confusion that often occours on that thing. What do you think about this?

Cheers.

fishcakes
Posts: 2
Joined: Mon Oct 18, 2021 9:35 am

Re: Brandubh 7x7

Post by fishcakes » Sat Oct 23, 2021 5:45 pm

Hello all! I am working on a project to develop an AI to play Brandubh, but first I need to make sure I fully understand the rules (and some strategy as well!)

I saw earlier in the discussion that people were talking about ambiguity in the 3-fold repetition rule, and I was wondering if any changes to the rules were made because of this - such as white always losing in the case of repetition, or if someone could explain this in greater detail with some example games that have had repetition endings.

Also, I was wondering if there are any existing AI or strategy guides/discussions on openings, end game, etc. I feel that if a powerful Brandubh AI engine existed, it could shed some light on the balance of the game and be a contributor alongside the human perception of the game.

Irish Raven
Posts: 1
Joined: Sun Oct 17, 2021 7:53 pm

Re: Brandubh 7x7

Post by Irish Raven » Mon Oct 25, 2021 6:29 pm

Hi fishcake, you are right that the threefold repetion rule as applied to Brandubh on this site is still a little unclear. The printed Federation rules do not explicitly state that the 'white wins in any repetition case' has been accepted.
Hagbard can surely confirm if white always winning a potential repetition situation has been programmed on this site.
The only Brandubh-2 game that I have seen with a repetition ending (apart from the game mentioned previously in this thread) was one occurring in the game between Xerxes v unhandyandy (Brandubh-2 tournament June 2020) but there are probably others.
On this site a warning appears after two repetitions and this is probably enough motivation for players to try something different unless they are obviously lost.
Regarding the AI aspect there is another thread 'The state of Tafl online' where AI was discussed - unhandyandy and Hagbard might be able to add more.
Good luck with your project, I guess a strong AI engine would 'solve' Brandubh as it only lies somewhere between draughts and connect4 in complexity.

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