... by: Sunshine 28
Andrew, a fantastic site. I have become a sudokuholic.
Agree with Rasmussen and Vidyasagar. There are simpler ways to get the task done such as coloring. The point of the long winded answer I see is that we have to have more than one way to get there.
Again a fantastic site.
... by: ad.joe
Heureka, a name!!
In soccer (football) there is a "Bank of Four", in German Viererkette"!
(Oh God, finding this translation at last (has?) needed 2 years!)
So let's state:
THE BANK OF FOUR BUILDS A REMOTE PAIR!
Any opinions to that? Is it idiomatic English?
Of course there is a Bank of Six also, etc.
To Rasmussen: For me coloring (you can use it instead, yes) is always unnecessary and clumsy and a Remote pair is really simple:
One look at the whole grid says:
When the certain number is not on the first cell of the Bank of Four, it's definitely on the last! And so is the other number!
... by: Charles Rasmussen
Am I missing something here. Wouldn't simple coloring accomplish the same result and be a lot easier.
... by: Joe T.
The name "Remote Pair" refers to begin and end of the chain.
But: The way it works has to earn a name too (else newbys would say "Where's a pair?") which works as well:
In German we say VIERERKETTE (like the line of defenders in soccer is called). Does anybody have a better English word than "four man chain"?
(or 6 or 8 for Sechserkette/ Achterkette)
The full term of course would be:
"The VIERERKETTE creates a Remote Pair"
... by: csvidyasagar
You have tried to explain a rather complicated and advanced technique. But what I felt was you could have explained in simpler manner as under :-
(1) A (6,9) and B (6,9) are locked pairs and can call the line joining them as Link I as A and B are in the same Row. B and D are also locked pair being in the same box and the line joing them can be called as Link 2. D and E are also locked pair being in the same Row and line joining them can be called Link 3. So you three links which are open ended - i.e not joined and forming a loop . So A is same as E and B is same as D . When you have odd links i.e .1, 3, 5 the cell Z ( 8,9)lying in the intersection of these ends i.e. A (6,9) and E (6,9) can not have one of the numbers in it and 9 can be removed from cell Z which now has only 8.
2) In the second example of seven locked pairs, you can follow the same explanation as given in 1) and this will give the same result. A(3,8) and C (3,8)are Locked pair being in the same column and form Link 1; C and E are locked pair being in the same box and form Link 2; E and D are locked pair being in the same Row forming Link 3. A & E are Complementary pair and so is C & D. Therefore A and E are one and the same so is C & D. Since there are three links (odd), the cell Z (3,6,7,8) falling in the intersection of end of three links i.e. A & D can not have either of the numbers (3,8). So remove 3,8 from Z (3,6,7,8) thereby leaving only 6,7 in it.
3). The same logic applies to cell X (2,3,6,7,8). You can not remove any numbers from X as the links are not odd.
Route. A to C being in the same Column (Link 1), C to B being in the same Row (Link 2), B to F being in the same box (Link 3) and F to G(Link 4). The ends of link are A and G but they are four links (not odd)connecting one end A to another end G, hence you can not remove any of the numbers from cell falling in the intersection of two ends A & G.
This is simple explanation rather than the long winded one you gave will make understanding easier.