Mark Sweep's puzzles

For this year's UKPA open I teamed up with Lennart Muijres (Leonardo024) to create a puzzle set. I already had the idea to have an entire set using stained glass clues, basically due to a Stained Glass Yin Yang I really liked during 24HPC.  So we got together to figure out genres where this would be feasible, taking into account the final combo puzzle. For the combo puzzle we started setting together, after which we focused more on individual subgrids by ourselves.  We initially only had one puzzle per type and the final combo puzzle. However, we ended up making some extra easier puzzles so that there would be more things to solve in all difficulty ranges. Our full round (round 4) and all the other rounds from UKPA open 2026 can be found here . Below are just the puzzles I created along with some thoughts. Our entire round lasted 75 minutes and had a total worth of 455 points. Stitches (Stained Glass) I liked this combination more than I anticipated. I have also grown more fon...

Last year I had the pleasure to write a round for the 24 hours puzzle championship (24HPC) taking place after the WSPC in Eger, Hungary. I did this together with Chiel Beenhakker (bakpao) and Bram de Laat (Para), who are also both from the Netherlands.  Our round consisted of a total of 30 puzzles: 15 standard types and 15 variations where a certain element (clues, cells, or objects) was enlarged. While there was no extremely difficult puzzle in the set, nobody managed to finish it (which is the goal for a 24HPC set), just because of the sheer volume of puzzles. Chiel's and Bram's puzzles (round 2), as well as all other  rounds from the 24HPC can be found in the archive of chaotic_iak here , definitely worth checking out! I definitely owe a lot of thanks to Bram and Chiel for this round. Due to a major deadline (handing in my PhD thesis) I did not have much time. They took quite some load off my hands by contributing more puzzles (12 each) and Chiel formatted everything by him...

If you're here just for the practice puzzles, scroll all the way down to the bottom of this post. This post is also quite late after the WSPC, but I just did not have the time and motivation to finish up this post earlier. This was my third time participating at the world championships, being part of the Dutch B-team for Sudoku and the Dutch A-team for Puzzles. In general, I immensely enjoyed this event. It was very well organized, went smoothly, and most puzzles were of very high quality! So huge credits to the organization and author teams for making this happen.  WSC 2025 Individual ranking: 82nd/252 Team ranking: 17th/63  It was a nice surprise to me that I placed top 100 in Sudoku, considering I had not solved many prior to this championship (as all my practice goes into WPC). I did love the variation between rounds, with several rounds feeling quite different from regular Sudoku. For me that's perfect, as the weirder or more puzzle-like it gets, the better I tend to be a...