Strawman. Nobody is saying the 2700 will underestimate the 1300 and treat the game as frivolous.
if you are reffering to my comment, sorry. The history is past tense. They were highly rated players and were pounded into the ground like tent stakes. SWEET!
Rare? Granted. But to the topic's heading, entirely possible.
I guess maybe the higher rated players may have used your words as their excuse...but then, they wouldn't have been that highly rated, eh?
I'm sure Fischer was simply under rated. It doesn't mean his opponents under estimated him based on his age. Anyway, nobody else is making a statement that a 2700 will underestimate a 1300, thus it is a strawman.
<Madhacker> right - indeed, 3 0 is my favorite internet playing time. Funny that it's considered 'slow' nowadays.
With chessboards I generally go for 5 0, and 3 0 seems crazy to me - however 3 0 for the internet looks about right, as 5 0 makes me die of boredom when I have to sit there and wait for the other guy to finally MOVE...
So yes, by all means...
The underestimation you speak of is elusive. I mentioned it with Judit because I know from a friend who played her, and though being nice, had intended on mopping the floor with her.
Such did not happen. Bernie took the hit, she walked with the grin.
Strawman is (to my knowledge) if I blame the lights in the room where the games are being played. Or the weather.
But the simple fact is, a 2700 player IS a 1300 player until they actually reach 2700.
Not that difficult to comprehend, is it? I don't think any players were hatched from their eggs with 2700 stamped on their heads, right? It's a moo point (a cow's opinion) though, as it has nothing to do with actually playing chess. Only when that person gets their proper rating.
Or, maybe it WAS the weather? d=^)) I'm reluctant to mention this, but YOUR attitude here and now IS an underestimation of the possibility.
Intending to mop the floor with someone doesn't mean that person plays weaker.
You're thinking of the word "excuse." A strawman is a false argument created to be attacked by the maker of the argument.
You probably missed it, but the argument had evolved to state a player that actually plays at a 1300 level.
"therefore a more appropriate comparison would be, for example, a race where Usain Bolt is pitted against a 10 year old child, not yet ready to maximize their own potential in such an event"
Look, I will give you that in both situations, one guy is way better at something than the other.
Beyond that, your comparsion is invalid. If a 2700 misses a mate in 1, the 1300 won't necessarily be incapable of finding it.
It seems to me to be quite hard to find something in a race equivalent to missing a mate in 1 -- maybe if the guy trips -- but that's more comparable to one of the guys having a heart attack during a chess game -- more of an outside factor. There just isn't much room for variation in a race, other than fatigue. In chess, a win can only be had when someone makes a mistake, and so the exploitation of skill is much deeper than simply running faster.
I'm not sure if I am making a great distinction here, but my point is that, to claim that the two scenarios are of the exact same nature based purely on the point mentioned in my first paragraph, is much too shallow to be valid.
How about a 1000 beating a 2400?
Elubas then consider a race between Mario Andretti and a 16 year-old brand new driver on an otherwise pristine course. It comes down to simple ability. The difference in ability between the 2700 and the 1300 is not easily overstated.
In fact I would go further: a 1000 could probably beat a 2700 too, if we had an infinite amount of games being played between 1000s and 2700s.
So many people here have offered tons of things that would get in the way of upsets like these -- how could the blunder happen when the 2700 isn't under pressure; wouldn't the 1300 blunder first; the 1300 wouldn't see something the 2700 doesn't see; the 1300 wouldn't have enough technique to win the resultant position, etc.
I completely agree that each and every one of these things are huge obstacles in the upset occurring, and that's why it would almost never happen.
I'm just not sure that each component is, by the strictest definition, impossible. Sure, a lot of times when I play much weaker players and I blunder, they don't see it either because they assume I won't blunder. Does that mean such a scenario is doomed to happen every single time I blunder? Not at all! There have certainly been times where my lower rated opponent did in fact find my blunder and took advantage of it!
And yes, it really does occur, sometimes, that the higher rated player blunders before the lower rated player. The way a higher rated player intuitively feels a position, how he blunder checks (checking for hanging pieces, fork patterns, etc), will certainly reduce the chances that he will make a mistake, but I don't think it's perfect.
Just like how in poker you can do everything the wrong way and still win, such can also happen in chess. If you don't blunder check a move before making it, that simply means that if the move is wrong, you won't know about it. However, that doesn't mean that the move can't turn out to be flawless anyway.
This all boils down to the fact that, although being wise and intelligent about something can "improve your fate," it cannot "completely control it," and that means that sometimes bad things will still, occasionally, happen to you.
In this case, fate would have to go way, way wrong, but I don't think it's impossible.
Elubas then consider a race between Mario Andretti and a 16 year-old brand new driver on an otherwise pristine course. It comes down to simple ability. The difference in ability between the 2700 and the 1300 is not easily overstated.
I'll remain with the running since running as a form of competition is extremely pure, and the contrast it has with chess might make my point easier to show:
For a runner to win, all he has to do is run better; in chess, playing better does not guarantee that you will win or even draw.
I should define better in terms of chess: I would say that it means that, the way you approach the game, will make it easier to control your fate. For example, checking for hanging pieces is better than not doing so, because if you don't, you have to pray in fate that you haven't allowed your opponent to take one of your pieces; whereas in the former case, you make sure that your pieces aren't hanging. But of course, you can only be as sure as your perceptions are: If your eyes are playing tricks on you and somehow you misjudge whether a piece is hanging or not, then you will still hang the piece even with the blunder check. It's just that you will hang it less often.
Plan:
1. Earn a rating of 2700
2. Play 1300s thousands of times without getting bored.
I am of course answering the question in a very theoretical way. In the practical world, you should never in a million years (literally) expect this kind of thing to happen, or you'd be a fool.
In a gazillion million billion trillion years, though, maybe it's not so unwise to expect it 
I keep posting though because there are people who literally think it's impossible, even when talking theoretically.
Not that such people might not be right -- I certainly can't be 100% sure of the answer myself.
But the simple fact is, a 2700 player IS a 1300 player until they actually reach 2700.
Actually, no. My initial non-provisional rating was over 1400.
Almost impossible, but... The way it could happen is when the 1300 is at his best that day and the 2700 plays loose and fast because he knows his opponent is "only" 1300, and yet....
The 1300 player will surely make the last mistake...
Someone i know (2100) just beat topgrandmaster Ivan Sokolov (2699) in a normal time control lague game though
Sure, maybe I could beat a 2700.
And Maybe I could get a lucky punch and knock out Mike Tyson, too.
But I aint holdin my breath to try that, either.
best chance to start the match and the 2700 gets a computerproblem, indeed is forced to time-out...
<Kenpo> He will sooner or later get a point against you, you know...
Yes, but 2700s tend to see checkmate very very well...
And a 1300 isn't at all likely to get into a position where he or she has checkmate against a 2700...