Let me elaborate on this rule

For a house(row/col/block), suppose that there are k cells that are not found yet (with more than one candidate), two of these are UR cells

When we have a UR naked set of degee ceil(k/2) there will always be an equivalent hidden set of degree floor(k/2).

When ceil(k/2)=floor(k/2) SE will ignore the hidden set of degree floor(k/2)

For all UR hidden sets with degree <ceil(k/2), SE will find these hints

EDIT: After all the hints that were not ignored are found, a hint with the lowest rating out of them will be used for the rating

Regarding the SE UR type 3 current rating

The rating of a UR naked set of degree j is 4.5+0.1*(j-1)

The rating of a UR hidden set of degree j is 4.5+0.1*(j-2)

I think the original intention was that the rating of a UR hidden set of degree j would be 4.5+0.1*(j-1), that is also what the comments statelksudoku

let me now try to apply that to the last situation (rated 4.6)

and to try another wording for any situation

- Code: Select all
`A B C |D E F |G H I`

1 5789 2 |5689 5789 456789 |3 69 4689

3789 4 379 |13689 13789 6789 |268 5 2689

6 589 39 |3589 34589 2 |7 49 1

--------------------------------------------------

3579 679 3679 |2 589 1 |4 79 389

3579 12 3479 |589 6 4589 |1258 1279 2389

459 12 8 |7 459 3 |1256 1269 269

--------------------------------------------------

2 689 5 |4 1389 689 |16 136 7

79 3 4679 |1569 12579 5679 |126 8 246

478 678 1 |368 2378 678 |9 2346 5

we work on column "H" UR r56c8

here k=7.

As in the "degree" we include one "equivalent cell" for the UR,

we can not have the condition "equal", so the hidden set must be considered.

we have a hidden triplet rating 4.5+.01*(3-2)=4.6

If this is correct, I could have spent hours on examples before having understood the rule.

So hidden sets are omitted only if k is an even number and only if the hidden set size is then k/2

three possibilities:

k=8 with a hidden quad

k=6 with a hidden triplet

k=4 with a hidden pair

this is somehow simpler that what I understood, but with a rating "depending on the set size".

the final table should be

- Code: Select all
`UR UL`

hidden pair 4.5 4.6

hidden triplet 4.6 4.7

hidden quad 4.7 4.8

nacked pair 4.6 4.7

nacked triplet 4.7 4.8

nacked quad 4.8 4.9

Hope to be now close enough to the truth.

I am waiting for your ok to think of the final coding.

champagne