I'm all for giving credit where credit is due (and make sure to), but as we rebrew and tweak a recipe from its original form it is becoming something else. Some changes, like a hop substitution for availability or preference, don't really change the beer much from the original. Other changes however, like fermenting an ale recipe with a lager at lager temps, will radically change the end result. And, as probably is more-so the case, there may be a whole series of progressive changes over many brews that sculpt the beer to the preferences of the new brewer.
I honestly don't have a fixed opinion on this myself (hence the thread), but I'm thinking it depends on both the uniqueness of the original recipe and the uniqueness of the variation(s). For someone's bitter with Maris Otter and some crystal, that baby pretty much becomes yours as soon as you start tweaking it. For something like a Janet's Brown, which has a very unique malt and hop bill, I feel you'd have to make some REALLY significant changes to the point that it is almost unrecognizable before it has been altered enough for it to be called your own.
Where is everyone else's head at on this question?
One note though... I do think you can name the beer something unique with fairly minor changes for casual enjoyment and sharing, though that line should be a bit more strict when naming competition beers. I'm talking about when you switch from saying "based on such-and-such's recipe" to "my recipe".




