I’m a big fan of geocheckers for a number of reasons.
Firstly, since finders have to plan their caching trips, and make the effort to drive somewhere and walk a variable distance to find a puzzle cache, I think it’s just a courtesy to supply some means for checking the accuracy of the solved puzzle, where it’s necessary. Checksums can be useful in this regard, but they are not 100% reliable.
Some puzzles need a checker more than others. Where questions need to be answered individually, a single wrong answer can scupper the whole solution, so it’s reassuring to be able verify answers before venturing out. In other cases there may some ambiguity about answers, or resources that give conflicting answers. Other puzzles give a vague clue to which there may be many interpretations. A geocheck gives a solver a means to try one or two alternatives, where there is any doubt. This can be abused of course in the “blanket bombing” tactics you’ve mentioned, Dave.
Some puzzles have a clear and explicit answer, once the key is discovered, so don’t really need a checker, as the solution is clearly correct when reached. This is why some of my puzzles don’t have checkers on them. And Dave’s “Moor – Casual Danger” cache is just such a puzzle with an unambiguous solution.
Another reason that checkers are useful is when the solution reached by the puzzle is subject to some variation, as in the cases you Dave mentioned. This allows the puzzle setter to give an exact solution to a finder where it’s not possible to reach the right answer with the information given in the puzzle alone.
The final thing that checkers are good for is to give supplementary information to a finder that is conditional on solving the puzzle. For example, you can give locations for trail heads or parking which would be useful for the finder. If these were listed in the cache page itself, it might give a clue as the final’s whereabouts.
When it comes down to supplying a checker, I’d much rather make it easier for a genuine solver to enjoy finding the cache than to penalise everyone for an individual who wants to circumvent the puzzle.
