Thank you so much for posting these Sudoku tutorials. I find the strategies to be exciting, yet frustrating at the same time. Frustrating only because the memory of how and when to apply them keeps slipping away. Hopefully practice will help nail it down, so I am especially grateful that you will be giving us the next video to help fix the memory of today’s strategy into place! Presently I find myself stumbling towards completion, rather than solving with greater efficiency.
Very clear explanation on locked candidates. I like you use the underlining and circle animations to emphasize your points. I am looking forward to your next Sudoku video.
Assuming you refer to 3:18, it is because column 1 has 4’s in 2 positions, both in the lower block, so the 4 for the lower block must be in column 1. Column 3 has 4’s in the upper block and lower block, so the 4 for column 3 may be in the upper or lower block at this stage (turns out, it must be in the upper block).
Hi, I just came across this video. I have been playing sudoku for six months and I find the definition of a triple confusing. Everyone I asked told me the same thing. For a triple to be valid, the set of 3 candidates must be exclusive within the 3 cells and they cannot be found in other cells but this video just proves that definition wrong. In this video, the 3 candidates in the first col of the block in question 1, 2 and 4 are in other cells too and they are eliminated. A couple of comments already pointed this out. I have found in many puzzles that one or more of the 3 candidates of a triple is often found in other cells but that does not negate the validity of the triple. I find that super confusing. Under what circumstances can a triple be valid even when its candidates are not exclusive within the three cells? Would the expert poster care to clarify this issue please? Thank you!
Hey Kenneth, let me explain triples a little better for you. Your current definition "the set of 3 candidates must be exclusive within the 3 cells and they cannot be found in other cells" is simply not accurate. A triple exists when there are 3 cells within a house (row, column, box), that contain at most 3 unique digits. (the logic is the same for pairs, quads, etc). When you identify N cells that contain K=N unique digits, since those cells cant be equal to each-other, then those cells must contain exactly those K unique digits. So then that lets you eliminate those digits from other cells within the same house. Hope this helps!
@ Hi Jeremiah, Thank you for taking the time to respond. After playing a few more months, I am getting better at identifying a triple. Have a nice day!
@@kenmiu1273At 3:58 the 1,2,4 are the only 3 choices in the lower block for column 1. So it is a triplet for that block and all 1,2 and 4’s can be eliminated from other cells in that block. Separately(!), column 1 has those same 3 numbers and cells as a triplet, so 1,2,4 can be eliminated from column 1. Separate issues, that happened to overlap here. A triplet is 3 numbers and 3 cells in a house (row,column or block) where ANY solution MUST contain one of those 3 numbers in each of those 3 cells. PERIOD! Jeremiah described a naked triplet, where no other number than those 3 are in those 3 cells within some house. You can see those 3 numbers (or less) in those 3 cells, nothing else, they are naked. In that case, the other 6 cells in that house (row,column,block) can no longer contain any of those 3 numbers. Eliminate them from OUTSIDE those 3 cells (but within that house). There is also a hidden triplet, where 3 numbers appear in ONLY 3 cells of a house. In that case, any of the other 6 numbers beyond those 3 can be eliminated from WITHIN those 3 cells (of the hidden triplet), making a (now useless) naked triplet (for that house, at least). Confusion arises because people are imprecise: A) In the definition of a triplet. B) Whether they are talking about a naked or hidden triplet. C) Talk about a naked triplet (as a ‘triplet’, as if there is only one type) when you may have seen both a naked and a hidden but not known there are two types, and therefore you have conflicting ideas that come from mixing the two. D) Whether it matters that the 3 triplet cells are both in a column and a block (it doesn’t, columns and blocks and rows are separate considerations). A triplet is within a single house; intersecting two houses is merely a confusing coincidence. At 3:58, there are 3 cells in a column (and a block) that only contain 3 digits, 1,2,4. So these 3 cells MUST consume them. This is a naked triplet. The other 6 cells in that column MAY (hopefully!) have some of these same 3 digits as candidates. Eliminate them. There is no necessity to the 3 cells being in BOTH a single column and a single block. Consider the column and block separately; this is not an XY-wing, involving two intersecting houses. You can identify a hidden triplet and convert it to a naked triplet. But that naked triplet is useless within that house (because if the other 6 cells in that house contain any of those 3 numbers, you didn’t have a hidden triplet to start with, right?).
Subsequent to my comment, I realized that the 4s in col 3 of Box 7 can be eliminated because of international interference (forget if this is the correct term). Also, the 6 is a naked single. But, my comment still stands.
These are by far the best Sudoku tutorials. Clear, concise, not a wasted word or distraction. Thanks!
Thank you so much for posting these Sudoku tutorials. I find the strategies to be exciting, yet frustrating at the same time. Frustrating only because the memory of how and when to apply them keeps slipping away. Hopefully practice will help nail it down, so I am especially grateful that you will be giving us the next video to help fix the memory of today’s strategy into place! Presently I find myself stumbling towards completion, rather than solving with greater efficiency.
Very clear explanation on locked candidates. I like you use the underlining and circle animations to emphasize your points. I am looking forward to your next Sudoku video.
Thanks Smart Hobbies, I just posted a Medium level "solve with me", I hope you enjoy it! th-cam.com/video/E15LVYtyp6g/w-d-xo.html
This actually helped me, thank you
Again. thank you for such clear concise explanations😀
So nice of you, thank you!
Thank U for Ure videos. I have a question. why do u eliminate the 4s in G3 and H3? and not in G1 and J1. Thak U
I was wondering the same thing
Because we are eliminating Line 1.
Why aren't the 4s in column 3 and block 7 not the locked candidates eliminating the 4s in column 1?
Assuming you refer to 3:18, it is because column 1 has 4’s in 2 positions, both in the lower block, so the 4 for the lower block must be in column 1.
Column 3 has 4’s in the upper block and lower block, so the 4 for column 3 may be in the upper or lower block at this stage (turns out, it must be in the upper block).
Can’t wait to learn about x-wings, thank you so much for these videos they are very well done and your delivery is amazing ⭐️
Thanks Aidan....coming soon!
Hi, I just came across this video. I have been playing sudoku for six months and I find the definition of a triple confusing. Everyone I asked told me the same thing. For a triple to be valid, the set of 3 candidates must be exclusive within the 3 cells and they cannot be found in other cells but this video just proves that definition wrong. In this video, the 3 candidates in the first col of the block in question 1, 2 and 4 are in other cells too and they are eliminated. A couple of comments already pointed this out. I have found in many puzzles that one or more of the 3 candidates of a triple is often found in other cells but that does not negate the validity of the triple. I find that super confusing. Under what circumstances can a triple be valid even when its candidates are not exclusive within the three cells? Would the expert poster care to clarify this issue please? Thank you!
Hey Kenneth, let me explain triples a little better for you. Your current definition "the set of 3 candidates must be exclusive within the 3 cells and they cannot be found in other cells" is simply not accurate.
A triple exists when there are 3 cells within a house (row, column, box), that contain at most 3 unique digits. (the logic is the same for pairs, quads, etc). When you identify N cells that contain K=N unique digits, since those cells cant be equal to each-other, then those cells must contain exactly those K unique digits. So then that lets you eliminate those digits from other cells within the same house. Hope this helps!
@ Hi Jeremiah, Thank you for taking the time to respond. After playing a few more months, I am getting better at identifying a triple. Have a nice day!
@@kenmiu1273At 3:58 the 1,2,4 are the only 3 choices in the lower block for column 1. So it is a triplet for that block and all 1,2 and 4’s can be eliminated from other cells in that block. Separately(!), column 1 has those same 3 numbers and cells as a triplet, so 1,2,4 can be eliminated from column 1. Separate issues, that happened to overlap here.
A triplet is 3 numbers and 3 cells in a house (row,column or block) where ANY solution MUST contain one of those 3 numbers in each of those 3 cells. PERIOD!
Jeremiah described a naked triplet, where no other number than those 3 are in those 3 cells within some house. You can see those 3 numbers (or less) in those 3 cells, nothing else, they are naked. In that case, the other 6 cells in that house (row,column,block) can no longer contain any of those 3 numbers. Eliminate them from OUTSIDE those 3 cells (but within that house).
There is also a hidden triplet, where 3 numbers appear in ONLY 3 cells of a house. In that case, any of the other 6 numbers beyond those 3 can be eliminated from WITHIN those 3 cells (of the hidden triplet), making a (now useless) naked triplet (for that house, at least).
Confusion arises because people are imprecise:
A) In the definition of a triplet.
B) Whether they are talking about a naked or hidden triplet.
C) Talk about a naked triplet (as a ‘triplet’, as if there is only one type) when you may have seen both a naked and a hidden but not known there are two types, and therefore you have conflicting ideas that come from mixing the two.
D) Whether it matters that the 3 triplet cells are both in a column and a block (it doesn’t, columns and blocks and rows are separate considerations). A triplet is within a single house; intersecting two houses is merely a confusing coincidence.
At 3:58, there are 3 cells in a column (and a block) that only contain 3 digits, 1,2,4. So these 3 cells MUST consume them. This is a naked triplet. The other 6 cells in that column MAY (hopefully!) have some of these same 3 digits as candidates. Eliminate them. There is no necessity to the 3 cells being in BOTH a single column and a single block. Consider the column and block separately; this is not an XY-wing, involving two intersecting houses.
You can identify a hidden triplet and convert it to a naked triplet. But that naked triplet is useless within that house (because if the other 6 cells in that house contain any of those 3 numbers, you didn’t have a hidden triplet to start with, right?).
Why last line is blocked
Subsequent to my comment, I realized that the 4s in col 3 of Box 7 can be eliminated because of international interference (forget if this is the correct term). Also, the 6 is a naked single. But, my comment still stands.
7 is also a naked single. This is not a good example to illustrate my comment.
Looking forward to x wing explanation
Thanks Cathy Arp, I appreciate the comments!
BRO WHAT WHY I CANT I UNDERSTAND
same here, it's so frustrating because there is not a real explanation. Why can we eliminate an entire column of 4? Can someone please enlight us?
lol