I recently stumbled across this website, by a Go enthusiast named Harry Fearnley
A lot of interesting content about seki (including hanezeki and nakade) and “beasts” (peculiar positions that are difficult to understand and potentially challenge various rule sets).
This is a bit like an Antarctica of Go for me!
A beautiful and vital place that makes the world the beautiful place that it is, and I’m glad that it is there, but I can’t see myself going there because it is too challenging 
You might also be interested in Richard Hunters series of articles also in the British Go Journal. He republish the articles in book form as The monkey jump workshop, cross cut workshop and Counting Liberties and capturing races.
Specifically the last one I mean, apparently they’re found in issues 102 to 120, so you’d have to look through them (not too bad they have tables of contents and things) just to see which ones are the capturing race ones.
The book is fairly cool, lots of discussion of when groups in capturing races end in seki.
Worth a bump
@Eugene’s Antarctica metaphor is interesting, but I think it can only be extended so far.
While I agree that Harry Fearnley’s work is indeed quite beautiful although esoteric, I think that one should not be scared away from it for it being “too challenging”.
Unlike a physical endeavor, such as an Antarctic expedition where failure could be life threatening, Go is purely a mental pursuit where challenges, mistakes, and even failure can never kill us, but only make us stronger.
True, but there’s also the question of where to invest effort, and what return there is from that investment… a look at Antarctica photos is low investment and modest return, and much like a quick look at that website 
Then I think that also depends on how we measure “returns”. If we only care about getting stronger as quickly as possible, then maybe one never needs to see what Harry Fearnley has done. But I think if one is interested in the possible complexities of the game, purely for the sake of its beauty, then not experiencing what he has to offer would truly be regrettable. Further, I think some of his work could yield starkly new, eye-opening perspectives that might even benefit one’s rank.
Were any of the Antarctic or Everest expeditions really worth the effort? How about the moon? What does humanity or the individual really gain from having gone there? Were these not worth the blood and treasure that they cost?