Title: Speculations; alt-text: 'I was pretty good at skeet shooting, but was eventually kicked off the range for catching the clay pigeons in a net and dispatching them execution-style.'
Well, I'll say one thing for Munroe's craft - I initially thought the subject matter of the conversation had anything at all to do with the joke. More fool me, however; it is just chat to fill time and establish that they're playing catch. Which is good because if it was actually important, the fact that the guy facing right suddenly becomes the guy facing left would wrong-foot us (are some motion lines to show him turning too much to ask? Oh well).
But that's not the joke. What is the joke is that instead of catching the ball as one would be expected to do in his situation, Mr. Hat takes 'catch' to mean 'hunt, obtain' and shoots it with a crossbow (because crossbows, like Google+, are nerdy and cool)*. This is an idea which is extended in the alt-text. It isn't a particularly funny idea, but you can't have everything.
He shot the ball. So what? He's Mr. Hat, he's not the 'catch' type, he's a classy asshole, remember? This is assholish and it's, er, classy? (because it's a crossbow?) so it's in character so it must be funny. No. The alt-text is a more amusing situation - in clay pigeon shooting you are actually expected to shoot them, so his finding a circuitous way of shooting them is more amusing than completely misinterpreting the meaning of the word 'catch' - but it's not very well written (it's the juxtaposition of 'skeet shooting' and 'the clay pigeons' I don't like - think for instance of the sentence "He threw the ball at me, and I caught the orb." Orb and ball do mean the same thing, true, but the use of synonyms means the two halves of the sentence don't seem connected. So yeah I'd rewrite the alt as 'clay pigeon shooting' and 'catching the targets in a net') and in any case it comes attached to a comic that might fool you with its 'nerdy' conversation but is, in fact, incredibly slight and, incredibly, not funny.
But never mind. jpk rides to the rescue:
Maybe he just couldn't come up with a punchline. Cancer's a bitch, he's got stuff on his mind. Happens.Sigh. Goodbye now.
*And he does it without looking, too! That's like so megacool crowning moment of awesome Mr. Hat is a BadassNormal etc etc aaaaargh killllll meeeee
I know I'm pushing this in every medium I can find (xkcdsucks, the xkcd forums, and now here), but we can't let the second panel off easy with just "the character positioning is wrong" as the criticism (though it is). The thing that gets me, as it's possibly the worst part of the comic (except the total lack of relevance between the setup and punchline), is that Randall's making an awful analogy while being completely oblivious of the fact that he just admitted to having no social life in the real world. That's our Randall!