Copenhagen Hnefatafl

[edmond_dantes]

there is nothing terrible in the white to have a draw in this game because if we look at the game in detail we will see that the blacks play very passively and help the appearance of this fort. The blacks play for siege but make a mistake with the K10 field, sacrifice a viking and have 50 moves that can lead to a narrow fort and a repeat of the position. Changing every rule to a worse score for white is not good. For me in this party, the fair result is drawn because blacks are not played correctly

[nath]

Is there a real reason we want those draws anyways? 8/8b seem to strongly contradict rule 10. Why not simply declare this a black win? We did that in in various offline games, since that removes the dire need for an umpire all the time to decide with rule takes precedence (which is highly subjective anyways).

[Hagbard]

Copied from small forum 2021-04-12:

Just a small historical comment:
Before 2012 we had only Fetlar here (and two Skalk variants which do not work), and I believe half the games were draw by eternal check and some by draw fort.
2012 Adam, Tim and I discussed a new rules set modified from Fetlar (which became "Copenhagen"), and Adam Bartley was the one who insisted on getting rid of all repetitions now that we were in the process.
It's informing to see that the ban on repetitions now comes so natural to the players, that it is greatly missed when it's not there -

[Hagbard]

Copenhagen games which ended in a draw because of too few pieces on both sides.

A draw is usually the result when black has less than 17 pieces and white less than 4 pieces.

These examples were found:
13.4.2022 Holidayinnes/Jilles. A draw was finally agreed after 18 rounds with no captures (18 white moves and 18 black moves).
6.3.2021 Herjan/Holidayinnes. A draw was agreed after 15 rounds with no captures.
5.1.2021 Holidayinnes/Frenir. A draw was agreed after 22 rounds with no captures.

There are also several examples of games with few pieces left, where the players agreed for draw after 1-8 rounds with no captures.

[Ytreza]

While browsing through the archive I stumbled upon this recent game between Casshern and Sqaree:

Casshern-Sqaree_small.png (82.53 KiB) Viewed 7725 times

Black won by timeout after 54 moves without capture. However White could have kept cycling inside the "draw fort" while progressively reducing its size to avoid repetition. This could have continued for much longer than 100 moves.

In this case, would it be a draw, or a loss for white?

---
Note: When playing with friends, I implement a winning condition for Black that is slightly different than the official one, that is, Black wins as soon as White cannot achieve his goals anymore, even if Black stops playing. Otherwise said, Black can "claim the win" at any point, after which White can freely move white pieces (possibly capturing black pieces) in order to reach a corner or build an escape fort.

This speeds up the end game where corners are closed and there is not enough space (or not enough defenders remaining) to build an escape fort. This also clears the situation above as Black wins as soon as the king is trapped on the edge. The game shown above would have been settled in 30 moves.

In practice it is pretty much equivalent to the official formulation. As mentioned in another thread, I also only forbid direct back and forth repetitions. Longer cycles lead to draws, provided Black cannot claim the win. This allows a restricted subset of interesting draw forts, hard to build in practice as they must be fairly large and involve the king, which cannot remain isolated otherwise Black claims the win.