Strictly on a technical level, Fisk's HR was an incredibly difficult play to call:
1) This was deep in extra innings of a World Series which stood at 3 games to 2. The stakes could hardly be higher, and you need to have that sort of dramatic impact come through in your call.
2) As soon as the ball leaves the bat, the commentator will want to convey that it's been very well hit.
3) He'll also want to convey that it's heading very close to the foul pole.
4) The foul pole is only 310 feet away from home plate, leaving very little time to make the call - and it was a line drive, not a high fly ball.
On top of all that, Stockton himself wasn't actually ready to make the call: he had just finished saying "...and the wind blowing out" when the ball arrived at the plate, whereas Martin had set himself with "The 1-0 delivery to Fisk - he swings..." and was braced for impact, so to speak. (That's not a criticism of Stockton as such, because no commentator will ever be perfectly set for every pitch in a long baseball game - sometimes you get lucky and sometimes you don't.)
I don't think Ned's call was perfect either, simply because "if it stays fair, it's gone..." uses too much of the limited time available to him. He was of course on radio and so had to convey more information to his listeners; on the other hand, Stockton had to hit his dramatic peak just after his viewers saw the ball hit the foul pole, whereas Martin had a fraction of additional time to finish the call before the crowd noise carried over the radio and the result of the play would become apparent. Either way, I think a better construction - just deconstructing the play after the fact and thinking what I might say given unlimited time to think about it - on radio would be something more like, "Long drive, left field -
will it stay fair? HOME RUN! Fisk hits one into the foul pole - the Red Sox win, and the series is tied!" (Or maybe, "Long drive, left field - toward the foul pole...HOME RUN!") And for Stockton, you could start with "There it goes - will it stay fair? HOME RUN!" ("There it goes - a long drive..." is redundant, really.)
Of course I'm nitpicking - I think the use of the word "perfect" to describe Ned's call probably set me off on this tangent
- but I think both calls have become famous because of the moment itself, not because of the calls themselves. THIS is a perfect call (albeit an easier call to make, and one for which Scully was perfectly set):
View: https://www.youtube.com/watch?v=0toCMwEBwLo
Anyway, in truth I never really liked Stockton's voice; he was a real professional in his prime (before age really started robbing him of his skills), but I'd struggle to think of a top play-by-play guy in his era whose pipes I liked less. And certainly I'm now glad that he's moving out and freeing up a new slot - hopefully for a good up-and-coming commentator - on Fox's NFL coverage in particular. But that's not to take anything away from those of you who remember him very fondly from his glory days.