Flashback #18 – Five Pair Sudoku

Let’s move on to a sudoku.
The first Five-pair Sudoku I saw was written by Vladimir Portugalov. Several followed in his Forsmarts website and his 24HPC sets. I like solving medium-ish puzzles so I keep that difficulty in mind when I’m constructing. Unless I’m out to get you (like a heavy-pointer in a puzzle set or a giant puzzle for last year’s WPC) I’m generally nice to solvers. 🙂

Five-Pair Sudoku: Classic sudoku rules apply. Additionally, each 10-cell grey area should contain two identical sets of 5 digits. The two grey areas may contain different sets.


Flashback #17 – Tetromino Minesweepers

Back in 2012, the UKPA held its first offline event in Manchester. I believe it was the only year that the organizers posted the puzzles online simultaneously for solvers around the world to compare their scores. The reception online was dismal so that idea was abandoned later on. I contributed some puzzles and sudokus for this event and I’ll be sharing my favourites over the next few weeks.

We’ll start with a tame Tetromino Minesweepers. I first saw this variant in Thomas Snyder’s old blog but I think there might have been earlier ones elsewhere. I’d love to know the history if anyone out there knows.

Tetromino Minesweepers: Place the 7 tetromino shapes into the grid; the shapes may be rotated but cannot be reflected. The numbers in the grid indicate how many of the adjacent cells (including diagonally adjacent cells) contain pieces of the tetrominoes. The tetrominoes cannot sit on the given numbers, and cannot touch even other, not even diagonally.



8 months without any events?
What’s up?
Out of ideas?

Nope, the exact opposite!
Around 40(!) puzzles have been written but I still feel the big picture is not ready. Also when one idea reaches the editing process, a bigger idea just craves to be made. I promise exciting things are to come but I don’t want to give any dates yet.

Offline things; last year, I won the Sudoku Northern Championship ahead of a field of almost 100 solvers (though mostly novice). The event is happening again next weekend and a tough field is travelling from Bangkok for my scalp. Sinchai is coming as well and he’s probably going to win it – the guy finished 10th in the Sudoku GP, uh, here take my title.

In the meantime, I’ll get through some more Flashbacks, which are currently about 5 years behind.
Until then!