Thank you so much Mark for featuring my puzzle. You did a very good job. Trying to color is difficult because of the color already added. When I tested it I ended up using corner markings. I do thank you for keeping it pure and not just picking a number. Although, that would have worked, also. I tried to use different shapes instead of involving colors. The problem was is I needed to find three shapes or have two shapes occupy the same cell. I was thinking on using arrows but at the time I was not able to figure out how to create that look. I spent a lot of time on just figuring out how to present the clues. When I would test it, I used A and B notation in the corner to denote high and low. The puzzle allowed center notation for the actual numbers so it was less confusing. The Black Kropki Dot was used as a disambiguator. As you saw in the solve it did not solve the high and low coloring. I do have Youri to thank for finding that disambiguator. He is a great solver and has helped me test many of my puzzles. Youri was able to narrow down the three dots I had previous to the one it has now. I find in this type of puzzle it will always need a disambiguator of some type. Without it there will be at least two possible answers. I think it's a fun new variant and I do hope it gets used again by someone else. I want to thank Mark and Simon for the kind words in their episodes today concerning my birthday and about me as a Sudoku Variant Creator. I have been watching for a very long time. This channel was my first introduction to Variant Sudoku. Before this channel I only knew of the 9x9 Sudoku where the only rule was "Sudoku Rules Only." I think my second or third puzzle I had created was the one they featured first and that was for their 3rd Anniversary.
When it comes to placeholder notation, if the worry is that it's bifurcation to place one "guess", what if you instead used letters? A through I, in order, and when it becomes disambiguated then you can either replace all As with 1s, Bs with 2s, etc., or replace all As with 9s, Bs with 8s, etc.
What an interesting puzzle and solve, Mark. I am glad that over time you have demonstrated how the placeholder technique works, and I'm also glad that you don't use it often in puzzles on the channel. I can imagine that it is helpful when solving privately because you are not arguing with anyone over the validity of the technique! My main desire in watching these videos is that you are enjoying the process of solving the puzzle, because that is fun for me as a viewer - and it seemed that you were in this puzzle. Thanks for this video!
For those who want a way to colour the grid, here's what I did: Mark all the green cells with a cross using the pen tool. Then go into the settings and toggle 'Hide Colours' to on.
A good way to mark the cells with a colour, whilst not obscuring the green is to use a flash colour. First of all select the entire grid (with Cmd-A or Ctrl-A if you're on a desktop). Then colour all those cells white (white is really transparent). Then you can go on to colour any cell you like individually, and it will show up as a flash. And you can still see the green cells.
I was out voting today, and that Guy Fawkes poem popped in my head. I've never looked up why we vote on November 5th, but now I'm curious if there's any connection. Also, this is a fun one!
America votes not on November 5th, but on the first Tuesday after the first Monday in November (i.e. the first Tuesday that isn't November 1st). The reasons are historical: because back when it would take a long time to travel, people in rural areas used to have to take a day to travel (walk, ride horses, ride in a cart...) to the city to vote. If election day were on a Monday, anyone attending church on Sunday mornings would only have a half day for travel, so they made election day Tuesday so that people could travel on Monday. And election day isn't November 1st so that people wouldn't have to travel on Halloween / All Hallow's Eve.
This year the first Tuesday that isn't November 1st happened to be Guy Fawkes Day, November 5th. But in 2022 America's election day was November 8th, and in 2026 it will be November 3rd. It's only November 5th approximately one year out of seven.
*Placeholder digits* are useful in multiple types of puzzle. For instance, puzzles based on lines that are insensitive to the transformation _y = 10 - x_ (e.g. German whispers, renbans, nabners, modular, entropic) or quasi-symmetric puzzles with limited disambiguators. If you want to know more about them, you can start by watching the CTC videos in my playlist. Thank you Mark for teaching us this powerful notation tool.
How come the title card at the start of the video isn't there? The one that says [puzzle name] by [setter's name]? I think this happened with yesterday's video too. Fun puzzle Jodawo, and happy birthday! Always like a bit of colouring. The negative constraint implication is pivotal and I didn't realise the implications for the difference between the perimeter cells is dictated by the number of circles/greens in the row/column for a while.
I finished in 66:45 minutes. This was a really cool idea for a puzzle that I can see being used more in the future. I was able to use a special technique that I created that helped me immensely. When only two digits exist in a cell, I split them into an upper section with the corner marks and a lower section in the center marks. It's effect is similar to placeholder digits, but also coloring. I was able to see when both digits saw a cell, similar to coloring. The other benefit is that is that like placeholders, the digits exist in the correct spot, so when I rule out one part, I rule out everything associated with that section. I don't usually use it on the entire grid, but on clues or boxes. I don't know if it is a form of bifurcation, which is why I usually restrict myself to a limited part of the grid. However, for this puzzle it felt necessary. I really enjoyed showing off my technique. Great Puzzle!
26:34. My break-in was doing math on the differences for each column and row, then plugging them in when available. Row 1 gave up easy for some reason. Fun puzzle.
You didnt follow the ruleset. Digits in circles in circles must be between the end digits. In the bottom row r9c1 and r9c9 could be 19. Yhe digit in r9c3 is not constrained by the rulesset so could be anything. You certainly didnnot explain or prove the additional rule. The 37 in r1c9 and 28 in r7c9 because of the single green in column 9. Wow. There is genius and there is knowing the answer from previously solving the problem. Mark, some of your solves, most are genious, but not this one.
Thank you so much Mark for featuring my puzzle. You did a very good job. Trying to color is difficult because of the color already added. When I tested it I ended up using corner markings. I do thank you for keeping it pure and not just picking a number. Although, that would have worked, also.
I tried to use different shapes instead of involving colors. The problem was is I needed to find three shapes or have two shapes occupy the same cell. I was thinking on using arrows but at the time I was not able to figure out how to create that look. I spent a lot of time on just figuring out how to present the clues.
When I would test it, I used A and B notation in the corner to denote high and low. The puzzle allowed center notation for the actual numbers so it was less confusing.
The Black Kropki Dot was used as a disambiguator. As you saw in the solve it did not solve the high and low coloring. I do have Youri to thank for finding that disambiguator. He is a great solver and has helped me test many of my puzzles. Youri was able to narrow down the three dots I had previous to the one it has now. I find in this type of puzzle it will always need a disambiguator of some type. Without it there will be at least two possible answers. I think it's a fun new variant and I do hope it gets used again by someone else.
I want to thank Mark and Simon for the kind words in their episodes today concerning my birthday and about me as a Sudoku Variant Creator. I have been watching for a very long time. This channel was my first introduction to Variant Sudoku. Before this channel I only knew of the 9x9 Sudoku where the only rule was "Sudoku Rules Only." I think my second or third puzzle I had created was the one they featured first and that was for their 3rd Anniversary.
Happy Birthday! This was a very interesting puzzle to watch Mark solve.
When it comes to placeholder notation, if the worry is that it's bifurcation to place one "guess", what if you instead used letters? A through I, in order, and when it becomes disambiguated then you can either replace all As with 1s, Bs with 2s, etc., or replace all As with 9s, Bs with 8s, etc.
What an interesting puzzle and solve, Mark. I am glad that over time you have demonstrated how the placeholder technique works, and I'm also glad that you don't use it often in puzzles on the channel. I can imagine that it is helpful when solving privately because you are not arguing with anyone over the validity of the technique! My main desire in watching these videos is that you are enjoying the process of solving the puzzle, because that is fun for me as a viewer - and it seemed that you were in this puzzle. Thanks for this video!
This is a real mind-bender! Such interesting logic!
47:49 for me - the hardest part was coming up with a scheme to track the high and low digits that didn't interfere with the green background.
For those who want a way to colour the grid, here's what I did:
Mark all the green cells with a cross using the pen tool. Then go into the settings and toggle 'Hide Colours' to on.
A brilliant idea for a puzzle.
Great puzzle! Took me embarrassingly long to solve, but still enjoyed it :)
Beautiful ruleset. I wonder why this hasn't made it to CTC more often.
A good way to mark the cells with a colour, whilst not obscuring the green is to use a flash colour. First of all select the entire grid (with Cmd-A or Ctrl-A if you're on a desktop). Then colour all those cells white (white is really transparent). Then you can go on to colour any cell you like individually, and it will show up as a flash. And you can still see the green cells.
I was out voting today, and that Guy Fawkes poem popped in my head. I've never looked up why we vote on November 5th, but now I'm curious if there's any connection.
Also, this is a fun one!
America votes not on November 5th, but on the first Tuesday after the first Monday in November (i.e. the first Tuesday that isn't November 1st). The reasons are historical: because back when it would take a long time to travel, people in rural areas used to have to take a day to travel (walk, ride horses, ride in a cart...) to the city to vote. If election day were on a Monday, anyone attending church on Sunday mornings would only have a half day for travel, so they made election day Tuesday so that people could travel on Monday. And election day isn't November 1st so that people wouldn't have to travel on Halloween / All Hallow's Eve.
This year the first Tuesday that isn't November 1st happened to be Guy Fawkes Day, November 5th. But in 2022 America's election day was November 8th, and in 2026 it will be November 3rd. It's only November 5th approximately one year out of seven.
*Placeholder digits* are useful in multiple types of puzzle. For instance, puzzles based on lines that are insensitive to the transformation _y = 10 - x_ (e.g. German whispers, renbans, nabners, modular, entropic) or quasi-symmetric puzzles with limited disambiguators.
If you want to know more about them, you can start by watching the CTC videos in my playlist.
Thank you Mark for teaching us this powerful notation tool.
How come the title card at the start of the video isn't there? The one that says [puzzle name] by [setter's name]? I think this happened with yesterday's video too.
Fun puzzle Jodawo, and happy birthday! Always like a bit of colouring. The negative constraint implication is pivotal and I didn't realise the implications for the difference between the perimeter cells is dictated by the number of circles/greens in the row/column for a while.
Also love how the negative constraint unwound the 45 pencil mark in r5c7.
Column 7 is what ends up breaking up the highs and the lows. Realizing that the end cells are consecutive and that one of them has to be odd.
In Australia, we just get a horse race.
I finished in 66:45 minutes. This was a really cool idea for a puzzle that I can see being used more in the future. I was able to use a special technique that I created that helped me immensely. When only two digits exist in a cell, I split them into an upper section with the corner marks and a lower section in the center marks. It's effect is similar to placeholder digits, but also coloring. I was able to see when both digits saw a cell, similar to coloring. The other benefit is that is that like placeholders, the digits exist in the correct spot, so when I rule out one part, I rule out everything associated with that section. I don't usually use it on the entire grid, but on clues or boxes. I don't know if it is a form of bifurcation, which is why I usually restrict myself to a limited part of the grid. However, for this puzzle it felt necessary. I really enjoyed showing off my technique. Great Puzzle!
Ooooo a late night surprise post!!
two weeks in the spring, but only one week in the fall (the US changed this past weekend)
Not sure why the chapter marks don't match the video but it often seems to be the case.
Chapter marks (Rules, Start of Solve) are at wrong times today ?
26:34. My break-in was doing math on the differences for each column and row, then plugging them in when available. Row 1 gave up easy for some reason. Fun puzzle.
What a lovely puzzle and ruleset! And more approachable than you might think, so give it a try! 26:15 for me. 😄
US updates first Sunday after Halloween.
Did bro just try to compare an election to an insurrection?
You didnt follow the ruleset. Digits in circles in circles must be between the end digits. In the bottom row r9c1 and r9c9 could be 19. Yhe digit in r9c3 is not constrained by the rulesset so could be anything. You certainly didnnot explain or prove the additional rule. The 37 in r1c9 and 28 in r7c9 because of the single green in column 9. Wow. There is genius and there is knowing the answer from previously solving the problem.
Mark, some of your solves, most are genious, but not this one.
❤❤❤❤ well done Trump. Keep safe until.