Børge wrote:
What is the difference between a Killer and an Assassin? The difficulty?
Thanks for a great question! The only real difference between an Assassin and a plain killer is .....history. This is my take.
1. You are correct that the difficulty level is crucial. Ruud aimed his weekly killer (Assassin) to be at least
a notch harder than any of the main killer sites, especially Sudoku Online and Perfect Sudoku (including the forum members' puzzles). However, he still wanted it to be solvable for most advanced players so at times he would say about Assassin variants/versions, "too hard for the intended audience". In the rating system the forum developed (which the SudokuSolver Score was later based on), a 1.0 or 1.25 puzzle was the usual level of difficulty for an Assassin in contrast to 0.5 or 0.75 difficulty on the other sites. A 2.0 rating puzzle was "too hard for the intended audience" and would never make it as an Assassin.
2. It is handmade. However, this can mean different things to different puzzles makers. The most common meaning is that the cage pattern is handmade, not computer generated. I think Tarek is about to make a computer generated pattern which is a first for an Assassin as far as I recall. I'm OK with that since the next bit is the most important bit.
The most important meaning is that
the maker has solved it step-by-step, either by a software solver (Ruud used an unreleased version of Sumocue & Jsudoku) or entirely by hand solving. Generally nowadays, by hand solving. For me, "handmaking" means I don't use any software hints when solving the potential Assassin
yet do first check the
SSscore (but not the log). Others vet the log or solver steps. Ruud, for example, often made it clear that although software had done the step-by-step solving,
he was happy with the human difficulty level of each step. Mike (mhparker) does this (notice the use of present tense - please give us another one Mike!!).
I think we all use software to check for a unique solution up front with the possible exception of Nasenbaer and Para (more present tense
). Nowadays, I usually use
JSudoku to generate a unique puzzle, in the
SudokuSolver score range of 1.0-1.50, using the cage pattern I made on
Sumocue. I still consider the final Assassin "handmade".
3. BUT what
makes a good Assassin, and this is the part that is most intimidating, is it
MUST be interesting. Usually, this means at least one advanced killer (or vanilla) technique required, for example, "Killer Pairs" or 3-4 cell "hidden cages". It must not be tedious with just needing cage cleanups or many, many innies/outies that nibble away at the solution. You'll probably get hammered by the forum if you make one of these!
It is
NOT difficult-just-for-the-sake-of-it. For example, a few Assassins have ended up with a "1.75" rating by the forum which is very rare since most advanced players can't solve them satisfactorily. But, they have been posted anyway because of their interest value. Assassin 50, one which Ruud (presumably) saved up for the milestone 50, was extremely difficult, but it featured the first Killer UR in the series. If it didn't have this very interesting move available I'm sure it would not be an Assassin.
4. Last, it has the
personality of the maker stamped on it. For me, an introduction is essential to my full enjoyment of their puzzle. I want to know something of how the maker went about it. Did they have a particular solving concept when making the cage pattern? Is there an alternate solution that may be particularly interesting? How much difficultly did they have while hand-solving it? What rating do they give it (in contrast!) to the SSscore?
Even though Ruud hasn't made any Assassins for over a year, he set the standards that we still maintain. Thankyou Ruud!
Can't answer your other question.
Cheers
Ed