Do you mean at the very beginning of the game? If so there is a triple "2-7-9" at right-middle quadrant. So there will not be 2s, 7s nor 9s at that row. And there will not be 2s, 7s nor 9s at that quadrant. That's why I removed them. And there is also a "5-8" pair in that same line that helped me to remove some others candidates.
At 1:23, I don't understand how you came to the conclusion that '3' was in that square? I'm having trouble figuring this puzzle out on my own, but want to learn why I can't. Thanks
I put that "3" there because it couldn't be "4". It couldn't be "4" because the bottom-left quadrant had all its two "4"s in the same column I put the "3". So I know there will be a "4" in that column in the bottom-left quadrant, then the "4" cannot be in top-left quadrant in that same column. I hope the explanation is clear, but if you still don't understand, please let me know.
@@Daily.Sudoku PERFECT! Thanks for the response. Helps me see this stuff better. Although, on my puzzle, I still had a 7 listed as a possibility for Row 1 Column 2.. so that's why I guess I couldn't put a 3 there yet. I had the 4s in right place though. But now I also see that 7 has to be in the top/middle quadrant on row 1, therefor I could have eliminated that 7 and left me with 3. Thanks!!
@@RyanSandersGuitar If you look at top-middle quadrant, you will find a 1-7 pair at row 1. So "1" and "7" will be there, and cannot be in the top-left quadrant in row 1. Then you can eliminate that "7" at row 1 column 2.
1:25 watch here there is a triple "4-7" "4-7-8" "4-7-8" in column C lines VII, V and IV. Three numbers in 3 cells in the same column (exclusively) means they cannot be in any other cell in that column. So 4, 7 and 8 cannot be in C-II.
It says "Hard" in the screen, but it is "Expert" level. My mistake, sorry. I forgot to change the label. But here: 0:01 you can see it is really expert level.
7 at 3:57 => 7 was the only possible number there. 4 and 8 might be in the same row ("IX") but last columns (G, H, I). 3 at 5:46 => Once the center quadrant only have 3s in row "IV" so there is no 3s in columns H and I for row IV. Then the only place for 3 in center-right quadrant is there.
hum, I guess that was a mistake and luckily it came to be right. Probably I thought it was the only 9 in row 1, because F1 was selected and I didn't see there was a 9 there too.
Yep, hidden pairs may appear anywhere ;) But in this case it was not a pair, it was just the "8" in row 2, that could not be in 2nd and 3rd quadrants. So, in the first quadrant it should be in row 2, and shouldn't be in the other rows.