The New Sudoku Players' Forum

[PeetNeef]

Hey guys,

Another puzzle again. I can't work it out..

I hope the notes are clear.

(Type error, wrong picture) https://ibb.co/W0kxjcF

(Corrected, good picture) https://ibb.co/NyD1pLn

[Leren]

You have two 1's in Row 8, so you have made a mistake somewhere.

Leren

[PeetNeef]

Oh my bad, I copied everything from my sudoku book in an online grid and that 1 is a typing error, must have been a 2!

Can you have a look at it with taking into account that it's a 2 instead of a 1?

[PeetNeef]

Let me make it even more easy, here you go haha

https://ibb.co/NyD1pLn

[PeetNeef]

And can you explain me why r6c9 is not a BUG+1. The 8 appears three times and the other numbers only 2, I already checked and I can see that the final answer is not an 8. However, according to the undermentioned criteria I can't understand why in my example (which seems exactly similar), it is not a 8 (or 2 and 7 can be eliminated).

BUG+1 - Binary Universal Grave + 1
A BUG+1 is a possible BUG, where exactly one cell has one additional candidate. That candidate has to be placed to avoid the BUG.

The additional candidate is candidate 6 in r1c8 (it appears more than two times in at least one house). It can be placed (or 3 and 5 can be eliminated). This applies to the following screenshot: https://ibb.co/QpZxg8f

I can't see the difference between both examples. The additional candidate in their explanation doesn't seem different than in my example...

Can you please explain the differences in their and in my example?

[Leren]

Code: Select all

*---------------------------------------*
| 69 79  4679 | 1 34 5  | 8     2   37  |
| 2  5   3    | 7 6  8  | 9     1   4   |
| 1  8  b47   | 9 34 2  |a37    5   6   |
|-------------+---------+---------------|
| 68 1   5    | 2 9  7  | 36    4   38  |
| 7  3   26   | 4 8  1  | 26    9   5   |
| 89 4   29   | 3 5  6  | 1     78  278 |
|-------------+---------+---------------|
| 3  79  8    | 5 27 49 | 24-7  6   1   |
| 4  2  c79   | 6 1  3  | 5    d78 d789 |
| 5  6   1    | 8 27 49 | 24-7  3   279 |
*---------------------------------------*

A Grouped Skyscraper (AKA a Sashimi finned XWing) will get you home. One of cells marked a or d must be 7.

There is no BUG+1 here because 4 cells have 3 or more candidates. Note that r1c3 has 4 candidates.

Leren

[AndyP]

IMHO its easier to see
RU = remaining unknowns
RU Technique Details
28 xyWing eliminated 7 from F9 via chain r6c8 r4c9 r1c9.
26 RPchain:4 eliminated [7 9] from r1c9 via chain r1c2 r7c2 r8c3 r8c9.