by djape » Fri May 26, 2006 9:30 am
Ruud, the reason is your second step - "complex innies/outies". For unexperienced solvers this is not so easy to spot, plus, once you do spot it, you have to add 10 cage sums and subtract 3*45 from it. So there's lots of (simple) arithmetic and it's not an "automatic" operation.
Actually, if I plug-in number 6 in R6C1, PS v0.5 rates this puzzle only THINKER. Perhaps 2 increases in the level of difficulty for one "complex innies/outies" may be too much. So I'd say that BRAIN is about the right estimate of difficulty.
Like I said many times - difficulty levels are there just as a rough description of the puzzle. Realistically it's a very personal thing - Crazy Girl is an experienced solver, yet she had problems with this puzzle.
I find it funny when authors place "solving time" next to a puzzle. If it's there for marketing purposes - Ok, but otherwise it's as good as a random number.