Copenhagen Hnefatafl

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Hagbard
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Re: Copenhagen Hnefatafl

Post by Hagbard » Fri May 25, 2012 12:39 pm

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Why do the king's squares function as "hostile squares"?

The custodian capture of ancient board games represents the idea that two men in fight are always equals and noone can kill the other.

Supposing the king's squares represent walled strongholds, the man with his back to the square is however "fighting with his back against the wall" and is worse off than his opponent. As the fight isn't equal anymore, the pressed soldier loses, no matter which party he belongs to. Therefore the square is equally "hostile" to both parties.

MaC made a similar note of this:
MaC wrote:Did you ever try to fight with a wall in the back or at the abyss edge?

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Re: Copenhagen Hnefatafl

Post by Hagbard » Thu May 31, 2012 8:21 pm

Adam wrote:then our rule that we need 4 warriors to take down a king tells us that, for whatever reason, he needs to be attacked from all four sides ... Trapped he is, dead he is not, simply because we have already accepted that you have to have a fourth man to knife him in the back. ... An immobilised king is not the same thing as a dead one.
But does the king actually die in the capture-from-4-sides-games? Although no doubt the king is a fit fighter and first among equals, even a king doesn't possess the strength of four combat vikings. I'd say that in the capture-from-4-sides-games the king is captured alive for ransom - more worth alive than dead, not unusual of the times.

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Re: About the draw concept

Post by Adam » Fri Jun 01, 2012 11:47 pm

Hagbard wrote:I'd say that in the capture-from-4-sides-games the king is captured alive for ransom - more worth alive than dead, not unusual of the times. This also supports the idea in the note above that the king in the 4-sides-game is captured when and only when he cannot in the next move run away from the encirlement.
I'm glad you pointed that out, as I was about to make a post suggesting that if you can take the king against the edge, then ordinary soldiers should logically be taken against the edge too, which would create an absurd game where the king would escape every time.

I agree with your logic, the goal of black is to capture the king, as opposed to destroying the king.

That would just leave us with the potential problem of making things too easy for black again. Once again edge escape seems to be the simple answer, and we have previously agreed that it makes a well balanced game on the 9x9 (rachuneck/long ship tafl). However, I think what we are looking for is a rule set for 11x11 corner tafl that can function in a tournament situation.

I still dont see the need for the shield wall rule, though no reason not to try it out. Could be a nice addition.

Strong Copenhagen rules with a king hostile board edge, but king friendly corners then seems to be where we are ending up with this exploration?

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Re: Copenhagen Hnefatafl

Post by Hagbard » Thu Jun 14, 2012 5:07 pm

Adam wrote:With a black win encirclement rule, and a rule forbidding forced draw positions through perpetual stepping, we have no need to have a rule for taking the king with 3 men against the throne. I would suggest therefore leaving the throne as it is, and dropping the rule of taking the king against the throne instead of making it an impassable barrier. Mind you, my throne rule origins are a bit rusty, maybe we should have a throne as close to the historical sources as possible?
The advantages of a no reenter, no pass throne are:
  • First and foremost it makes the rule for king capture coherent. Instead of having several rules for different positions on the board, they're all unified into one single rule without any exceptions.
  • A throne change from reenterable, passable into no reenter, no pass, has very little influence on the outcome of the game, as the crusial fighting usually takes place at a distance from the throne.
  • A no reenter, no pass throne doesn't contradict historical sources. The first paragraph of the Linné diary rules says
    1. Arx regia. Konokis Lappon., cui nullus succedere potest.
    Transl.: Royal Citadel (or throne). Called Konokis in Lapp, no one is allowed to enter here.
    After studying the diary Latin source text, Ashton, Cartier, and not least Swedish historians reconstructing the Lappish Tablut, all arrived to the conclusion that the throne is non reenterable and non passable.
Adam wrote:leaving the throne as it is, and dropping the rule of taking the king against the throne instead of making it an impassable barrier.
This suggested throne on the other hand has some disadvantages:
  • In all known, current variants (to my knowledge) the king is captured against the throne by 3 blacks, so the suggested throne would be the first deviation from that principle.
  • Surrounding the king by 3 blacks and the throne without capture gives two possibilities:
    • either the king is unaffected by such surrounding, which would turn the throne's neighbour squares into king's refugees, also a deviation from known variants,
    • or else it must be demanded that the king moves away immediately in the next turn to escape the attackers. This line could result in a game continuation like:

      king surrounded by 3 blacks and throne
      king moves away to the throne
      king voluntarily moves back into the surrounding. Just like ordinary pieces can safely move in between two enemies, the king too should be able to do so safely.
      It will now take black two moves to renew the attack - which the king again can escape to the throne. Etc. etc.

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Re: Copenhagen Hnefatafl

Post by Hagbard » Sun Jun 17, 2012 9:39 am

After 5 months' fruitful discussion in this thread on virtually every aspect and problem of the Hnefatafl game, I propose "the Copenhagen rules" to be:

Rules of Copenhagen Hnefatafl 11x11.

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Re: Copenhagen Hnefatafl

Post by crust » Sun Jun 17, 2012 11:57 am

Congratulations - a very clear explanation with wonderful diagrams. Awesome!

3 questions: Does the computer already prohibit perpetual check and draw-by-repetition? How do you feel about preparing similarly clear explanations of other rule sets? Also, in Copenhagen rules, does the shield wall rule only work at the board edge?

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Re: Copenhagen Hnefatafl

Post by Hagbard » Sun Jun 17, 2012 12:16 pm

crust wrote:Does the computer already prohibit perpetual check and draw-by-repetition?
It does.
crust wrote:How do you feel about preparing similarly clear explanations of other rule sets?
A good idea.
crust wrote:Also, in Copenhagen rules, does the shield wall rule only work at the board edge?
Yes. The rule was found on a German site where it's explained to work this way.

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Re: Copenhagen Hnefatafl

Post by Hagbard » Tue Jun 26, 2012 8:58 pm

MaC wrote:

There is stil a undeclared draw-position,m if black blocks all corners each with minimum of three peaces and without enough peaces to capture a lonely king.
According Rule No 8, attackers win because they have more possiblilities to move, but who will count the repetitions? And who count the repetitions if the defender have more peaces but not enough to capture a running (moveable,free) attacker.

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Re: Copenhagen Hnefatafl

Post by Adam » Wed Jun 27, 2012 2:27 pm

Hagbard wrote:After 5 months' fruitful discussion in this thread on virtually every aspect and problem of the Hnefatafl game, I propose "the Copenhagen rules" to be:

Rules of Copenhagen Hnefatafl 11x11.
Lovely job, and well done everyone for putting in so much time and thought. I suggest we see how this finalised version plays in friendly games, and perhaps set up a new mini tournament in the autumn?

I am curious to see how the shield wall plays. I find it hard to imagine it ever getting to be used in practice, but I'll enjoy trying!

Also, I concur regarding the throne rule, Hagbard has made a good case for it being more elegant as it stands in his rule set. I am sure an impassable throne will infuriate me to start with, but it does seem to have the ring of authenticity about it ;)

Good work!

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Re: Copenhagen Hnefatafl

Post by Adam » Wed Jun 27, 2012 2:41 pm

MaC wrote:There is stil a undeclared draw-position,m if black blocks all corners each with minimum of three peaces and without enough peaces to capture a lonely king.
According Rule No 8, attackers win because they have more possiblilities to move, but who will count the repetitions? And who count the repetitions if the defender have more peaces but not enough to capture a running (moveable,free) attacker.
Good question Mac. Hagbard, how would the computer handle this?

In terms of human players, I think the solution will be obvious: either its a genuine draw; black can't capture, white can't escape, so a draw is agreed (but not forced) Or, white is so depleted that black can in fact abandon the corners with care and ultimately pin down the king. If the king is evading capture by means of fruitless, perpetual repetative evasion with no hope of advancing his position, no matter how complex this repetition is, then the players ought to agree that this is illegal play by white. And I maintain that it will be obvious who is at fault. In the genuine case where players feel both have played fairly but neither can advance, they can agree a draw (though the draw is not 'forced'). In reality I suspect one player will feel obliged to resign, or the deadlock will be broken and one player will gain the upperhand and win.

I'd like to hear how the computer will handle this.

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