kishy72 - 2017-10-02 5:58 PM

9.Battenburg Sudoku

Rules state all possible symbols are marked.Does the joker digit take its actual value when the vice versa rule comes into play or it could be any other digit ? For example, consider the following case with 5 as the joker digit : R1C1 = 1 ,R2C2 = 2, R2C1=4, R2C2 = 5 . Will this be marked by a Battenburg symbol or not necessarily marked ?

Hemant Kr Malani - 2017-10-02 5:57 PM

2. Pencil Marks sudoku
The rule says that 'the joker may assume any of the given pencilmarks in the cell' but in r9c5 this is not true.
3. Non-Consecutive
Same here. The rule says that 'the joker may assume any value that is not consecutive to the digit in its adjacent cell' but this is not true in many cells for example 4 is consecutive to both 3&5 in box 4.

Can you please clarify which is correct--the rule or example?(I think the example)

Para - 2017-10-02 6:15 PM



R8C23+R9C23 seems to confirm that it doesn't have to be marked.

Just to reiterate on this. If the Joker has to be a 4 to fulfil a Battenburg marking in one 2x2 square and a 4 in that cell would also fulfil a Battenburg square in another place, that second square does not have to be marked as that Joker can just assume a random other digit for this other 2x2 square that wouldn't fulfil that Battenburg square? (This is just how this round in general works, right? A Joker can be as many different digits to fulfil all possible constraints or missing constraints set in the puzzle.)

vopani - 2017-10-02 6:25 PM


2. In Pencilmarks, the digit '7' is the joker. R9C5 is a '7', the joker, and it can assume the value of '4' (or '5') to satisfy the pencilmark clue.


3. In Non Consecutive, the digit '4' is the joker. R5C2 is a '4', the joker, and it can assume the value of, say, '8' to satisfy non-consecutive constraint with the '3' to the left and it can assume the value of, say '2' (or even '8' again) to satisfy non-consecutive constraint with the '5' to the right.

The rule and example are both correct as per these descriptions.

forcolin - 2017-10-03 4:25 AM

8 Clock faces sudoku. I believe that the dot in the bottom left corner is of the wrong colour. In no way the joker can originate a clockwise sequence with the 2,4,6 placed in that way.

Also, why there is not white dot in the intersection R89 C23? in this case the 5 could be replacing a 7. Or in the intersection R78 C23, in this case the 5 replaces a 9.
This applies also for many other intersection where the joker is involved. In which sense the statement "All such dots are marked" should be interpreted?

detuned - 2017-10-03 6:40 PM

Ok, so there might be two equally valid interpretations of the joker, the one which forcolin outlines and the one which Rohan has outlined. So it becomes a question of which interpretation takes precedence.

Perhaps we need a statement along the lines of “there exists a value the joker can take so that the dot or lack of dot works” whilst making clear that is also possible to choose other values which break the rule. Rereading this entire round, it strikes me that this definition of what a joker is has not been adequately described to remove the ambiguities in the rules. Could I suggest this is added as a round note please?

jzverina - 2017-10-04 2:23 AM

Hi,
must be the joker always uniquely determinable? Example: in non-consecutive, if only numbers 4 and 5 break non-consecutivity (i.e. only consecutive pairs 45 appear in the grid), you can´t determine which of the digits is the joker. You need either 4 to touch 3 or 5 to touch 6 to uniquely identify the joker.

vopani - 2017-10-03 7:43 PM


We will review and get back on this.

TiiT - 2017-10-07 12:58 PM

Maybe it's easyer to understand if you think that a Joker can break any rules. If there is no battenburg sign and you know there is Joker in that 2x2 area, then it doesn't matter what the other digits are.

forcolin - 2017-10-08 10:17 PM
......, with the even number located below the joker.