cyningstan wrote:As a paid-up member of the awkward squad, I see an alternative interpretation of the find, though.

Please take a look at this full resolution photo of the Oslo board (thanks to Adam Bartley for sending this detailed photo!):

**http://aagenielsen.dk/oslofullrez_20140206.jpeg**
What can be seen of the marked squares suggests that all marking lines are carefully carved from edge to edge of a square, no sloppiness about that.

Square H7 is clearly marked with an "*" (a cross plus a vertical line).

Square G8 is clearly marked with a double lined "+" (four bows, one in each corner).

Squares D7 and D8 are clearly marked with a single lined "x" (lines from corner to corner).

Likewise are squares G4, H4 and I4.

The line of west x-squares are a distance of 4 squares from the *-square, whereas the line of south x-squares are a distance of 3 squares from the *-square.

This means that the *-square cannot be the center of the board, but it is the square right above "*", H8, which is the center of the board.

Square F4 is clearly unmarked. This means that the length of the x-markings is three; that is, there is a line of three x'es on each side of the board, distanced four squares from the center.

Studying rest of the squares where any marking would be visible, symmetry gives that there are no more markings on the board. Except perhaps for the center square H8, which is damaged, but knowing it to be the center, if you stretch your imagination, one can perhaps faintly see a double lined "*" there.

The rows from row 5 and downwards are preserved from edge to edge, and 15 squares can be counted.

So the Oslo board fragment looks like this:

Code: Select all

```
| - - - x - - + ?
| - - - x - - - * - - -
| - - - - - - - - - - -
| - - - - - - - - - - - - - - -
| - - - - - - x x x - - - - - -
| - - - - - - - - - - - - - - -
| - - - - - - - - - - - - - - -
| - - - - - - - - - - - - - - -
```

and the complete Oslo board would look like this:

Code: Select all

```
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
| - - - - - - - - - - - - - - - |
| - - - - - - - - - - - - - - - |
| - - - - - - - - - - - - - - - |
| - - - - - - x x x - - - - - - |
| - - - - - - - - - - - - - - - |
| - - - - - - - - - - - - - - - |
| - - - x - - - * - - - x - - - |
| - - - x - - + X + - - x - - - |
| - - - x - - - * - - - x - - - |
| - - - - - - - - - - - - - - - |
| - - - - - - - - - - - - - - - |
| - - - - - - x x x - - - - - - |
| - - - - - - - - - - - - - - - |
| - - - - - - - - - - - - - - - |
| - - - - - - - - - - - - - - - |
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
```

The X, + and *-squares are the five special squares where the king must be surrounded from 4 sides, while captured from 2 sides on rest of the board.

If a 15x15 game is played, the x-squares are ignored.

If a 9x9 game is played, the x-squares mark the edge of the board.

In this forum note I deduced and argued for that the rules are Tablut:

**http://aagenielsen.dk/hnefataflforum/ph ... &t=51#p524**
We've just tournament tested the Oslo board with Tablut rules, and the game balance found was excellent, 117 attackers' wins per 100 defenders' wins.

**http://aagenielsen.dk/hnefataflforum/ph ... rt=10#p600**
=======================================================================================

I can see your reasoning, cyningstan, it presumes that a row is missing between 5 and 6, and that the columns A and O and row 1 are not board squares. And then a 13x13 board would follow.

However:

On the full resolution photo one can see that the bottom edge of squares M1 and N1 is carefully carved with a double line. This means that row 1 are board squares and alas so the reasoning falls.

Having carved row 1, the carver realized that he'd done unnessecary work with those outer edge lines as the wooden strip marks the edge anyway, and so he spared the work when doing the column A edge.

And also, your interpretation requires the square D6 to be x-marked. And there's no trace of an x there, and although damaged, the square is after all just about so preserved that one could expect to see some trace.

Third, if the *-square H7 were board center, then for symmetry square G6 should be marked and probably with a "+" like square G8. Also, if H7 were board center, then the "+"-marking is diagonally to the throne, which does not make sense. (Whereas on a 15x15 board the marked squares are in line with the throne, marking four neighbouring squares.)

(But I cannot explain the strange crack E5-E6).