Because it's the classic definition of a "hack", it's a clever solution to an ugly problem. Not everything on HN has to be about javascript frameworks or making millions on startups. It's called "hacker news" not "san francisco tech startup echo chamber news".
The jigsaw technique is a cool hack. I'd never heard of it. And yep, you should post it. Random wikipedia articles like that make it to the front page all the time.
But this is not applying an idea from one area to another area -- it's taking the pre-existing idea and just applying it again. There isn't any novelty here.
On behalf of all of HN, I humbly apologize for there being a top news post of an event whose underpinning idea you had already read about and knew would probably work if it was put into effect in a situation like this. To prevent you from becoming emotionally harmed by potentially trite news, we will make sure never to post or upvote any story whose conclusion you might have guessed the outcome of.
We will continue to upvote every new JavaScript framework and tool, of course. After all, we're not unreasonable.
