> Spot the error or shut up.

That's not really how it works. I'm deciding whether it's worth my time trying to understand this. If it's really the breakthrough it purports to be, I can expect there to be some deep ideas and difficult tricks - I expect this to take both time and effort.

To decide whether I'll bother I apply several heuristics, many of which are well-known and informally documented. If the first page or two just seems like obvious stuff, or is subtly nonsensical, then I won't bother.

But I am certainly concerned that he doesn't cite any other significant work at all. More, the claims toward the end are rather, well, indistinct. It's doing very well against the ten heuristics in this blog post:

http://www.scottaaronson.com/blog/?p=304

OK, but I would love for those heuristics to focus on assessing the content of the paper, not the reputation of the author, his peers and quotations etc. You can get some vague impression of what's going on in this paper in some 30 minutes, there are many parts that seem strange (he says for 4-stage graphs one can manually verify that his "prooving algorithm" is correct and uses this as an assumption later in his proof), so I would love to hear something about that.

The heuristics I apply go well beyond the ones given in that post. In this case I have taken on board the fact that so many references are just to his own earlier work, and that work is old enough that it should have made a bigger splash. That's a clear indication that this is not likely to be correct, so I'm looking for mistakes, I'm not looking for deep ideas.

And I'm not finding deep ideas. I spent 10 minutes getting a feel for the approach, and I'll come back when I have another 10 or 15 minutes to spare, but it's really, really not looking good.

Well, the best heuristic is finding a mistake, and if it's a crank there should be several.

It doesn't always work like that. Sometimes a paper is, after enough trying to understand what's going on, simply nonsense. It can be hard work wading through pages of unmotivated and apparently random definitions, trying to find some sense, only to have it completely fall apart.

There aren't always obvious mistakes. Sometimes it makes sense locally, but not globally. Taking an early assessment can help enormously in avoiding time-wasters.