My favorite puzzle site is:
Each puzzle can be in 5 different configurations, with up to 500 pieces.
So we just finished a 1000p puzzle. The final 100 or so pieces were the sky - very hard to distinguish gradients of yellow and pink sunset. We really didn’t find that enjoyable. We sorted the pieces by shapes, and tried to sort by color, but beyond that, it was largely brute force - trying all similar pieces in each space.
Made me wonder how folk approach “upside-down” puzzles. Are you able to distinguish fine distinctions in a puzzle piece?
BTW - are there commonly used terms to describe the various pieces?
For example, I call pieces w/ 1 “male” projection and 3 “female” innies, “little men.”
2-opposite prongs w/ 2 opposite innes is “standard.”
4 outies are “crosses” and 4 innies are “swastikas.”
That’s interesting, because I usually start with the sky, and I find it much easier to sort fine color gradations than to make sense of muddled bits of picture.
Upside down cardboard is all about shape – without the distraction of pictures. I don’t do that, but I could see why one might. Upside down wooden puzzles have grain, and can be easier to do that the right side up version. I had one very tricky little puzzle with cut-outs (space between the pieces) that I gave up on until I turned it over, and then finished it without too much trouble. None of those pieces were “standard”, though, where by standard I mean “a rectangle with either a hole or a projection or a squiggly-kinda-flat-shape on each of the 4 sides”
I found the official names for the parts of a puzzle piece. The knows (male bits) are tabs and the holes are called blanks. Don’t ask me why.
And I sort by piece configuration when dealing with single color patches, like cloudless skies.
The trick for many puzzles is to break it down into minipuzzles. Since the complexity of doing a puzzle is the order n**2 where n is the number of pieces this reduces the time needed by a lot.
That was Dave Gorman in one of his “Modern Life is Goodish” programmes.
This bears a striking resemblance to the street map of the neighborhood where I grew up.