I always think standing closer is a terrible tactic. You go from catching the ones that carry to not catching any at all: from 50% to 0%. Has anyone ever seen a slip move a lot closer and actually catch a nick that would otherwise have fallen short?
That's an interesting one. And you make a fair point. You very rarely see it pay off.
I guess there could be an argument that it may change the way a batsman plays the ball - if hes using soft hands knowing it wont carry, and all of a sudden the fielder is there, it may cause him to do something different? That's a bit of a stretch though!
Another reason would be playing the percentages game. For a guy like Kane, you're more likely to have 5-10 edges drop short for every full blooded edge that would carry, so the likelihood of 1 in 5 or 1 in 10 half chances sticking is probably higher than a regulation edge carrying.