The New Sudoku Players' Forum

[ghfick]

Are there any examples of classic 9x9 puzzles with 2 TH? With one TH in, say, blocks 1, 2, 4 and 5 and the second TH in blocks 5, 6, 8 and 9. Can block 5 provide the same 3 digits for the 2 TH or possibly a set of 3 different digits for each TH? If there are many such puzzles, would any of these puzzles benefit in a "meaningful" way from the exclusions from both TH?

[Leren]

From Phil's Folly site.

The following puzzle (Regis, by Shye) has 2 consecutive type 1 TH's:

.12.3456.6.52.13.443.65....7..1.........2.........3..8....16.451.45.26.3.5634.21.

That is True if you ignore basic fish. You'll find that the TH's are slightly degenerate and an X Wing will eliminate the need for both TH's.

Put that puzzle into Hodoku, which doesn't do TH's and it solves easily.

Leren

[ghfick]

Thanks Leren,
The puzzle (Regis, by Shye) has 2 TH with 2 blocks common to each TH. Are there examples of classic 9x9 puzzles with just one block common to each TH?
Gordon

[champagne]

Hi Gordon,
here an example from mith's file

Code: Select all

.5.....21...6.2....3......6.24....67..12.64.8..8.7421.....61.7....7.8..2...42..8.
456 987 321
189 632 754
237 145 896

924 813 567
571 296 438
368 574 219

842 361 975
693 758 142
715 429 683

The solution grid has 2 TH,
one of type 2 in boxes 5689
one of type 1 in boxes 5623
The puzzle is for the first one and is rated very very high.
Many changes must be done in the clues , except may be in box 5, to have a puzzle with the TH in the second one
and we don't know if another very high rating is possible

and here both have the same three digits in the TH

[champagne]

Thanks Leren,
Are there examples of classic 9x9 puzzles with just one block common to each TH?
Gordon

This likely exists, but a puzzle hitting both and keeping the TH threat active would have too many clues -->> easy to solve