According to FIDE, if the difference between two player's ratings is 677, the stronger player has 99% chance of winning

If difference is 800, the chance of winning is, for all intents and purposes, 100%.

Here's a link to their handbook with the relevant table:

http://www.fide.com/fide/handbook.html?id=73&view=article

it has happened many times that a player defeated +800 rated than him , especially in simuls (there's a member here rated 1436, even about 1200 in live chess, and managed to beat a GM in an OTB simul.

Simuls aren't reated for a reason, FEDTEL ;)

Here's what I don't like about the rating system:

If Magnus has the highest rating of all time, does that mean he's the greatest of all time, or the greatest among his generation?  I think the rating itself is more a relative term than an absolute figure, so comparing players at their peaks based on rating isn't worthwhile.  If you get right down to it, the rating system is flawed when you put it that way.  I suspect the number will keep inflating, and the potential expansion of GM titles is indefinite.

Super duper bad mamma jamma grand master!

why? do you mean that masters don't play seriously? I know that they may allow a draw sometimes just to finish the games and go back home, but a loss? I think that's too much for them 

The rating system isn't flawed, it simply isn't meant to give one an historical ranking of players across eras. That's like saying a refridgerator if flawed if it isn't also a TV. While it might be a great idea, it isn't a flaw that it lacks that feature. Rather, it simply means it wasn't designed that way. 

Just because Carlsen's rating is relative to his player pool, doesn't mean his rating is necessarily inflated compared to other generations. It could mean that, but not necessarily.

If rating inflation is real, it definitionally means precisely that, since rating is a reflection of performance, and if his rating is not inflated with  regard to a prior era, but the rest of the pool is experiencing rating inflation, then his rating would be higher as his performance would be even better than it has been since he should be scoring better against the opposition than he is. 
 
Or perhaps more simply: ratings are calculated relative to one's opponents. If rating inflation is real, then Carlsen's rating has been calculated based on inflated values. This means his rating must be inflated as the inputs to the formula are infalted. 

It should be noted that there isn't universal agreement that rating inflation is real, or that if it is real, how big an impact it actually has. 

Maybe I am misunderstanding your post, but your first sentence is like saying "If A is real, then A must be real." Yes, but I'm not presupposing that A (inflation) is real. I am suggesting the possibility that his rating might be higher not because of inflation, but because of an increase in quality.

Of course, something that would prove rating inflation would be proving that the quality of Carlsen's moves are the same as of a previous generation, even with a higher rating. Some studies have shown that the intrinsic quality of the moves, not just rating, has gone up in general.

Agreed. I think that the middle ground is actually the real story. There is rating inflation, but I think the effect and impact is over-stated. The real big differentiator isn't rating inflation, but the ubiquitousness of computer-assisted training, the quality of the engines and the databases, and the fact that there is a strong pool of still improving players at the top. 

But I think the evidence for rating inflation is there as well, and I don't think it is easily ignored either. 

 

Lets say GM is 2700, playing a simul against 60 people who average at 1200.  Then lets say GM spends 15 seconds per move, making each turn 15 minutes long for the kids.  This is a huge time penalty for GM.  I once heard that the average game is considered 40 moves.    If all of the games go for 40 turns, this means the games last 10 hours, making it 10 minutes for the GM.  Whether the game draws or someone wins, the GM just cut his time down by 15 seconds per turn.

As you can see, with this simple hypothetical, this encourages GM to knock out as many of the kids as possible.  The weaker kids go first, either by a quick defeat or GM doesn't want to fight and offers a draw.  Then he gets some more time to deal with the more challenging players, but since he rushed the games, he might find himself to be up a certain creek without a paddle.  This is what leads to his losess.

I think this situation says that simul games shouldn't be rated.  Everytime GM draws against one of the kids, he loses hundreds of points.  GM would never do simuls, then, since the rating loss wouldn't be worth the money.  Of course, GM could just be paid for their 10 hours of work, which would cost a lot more money and therefore no one will fund the simuls.  Who wants to do 10 hours straight chess, either?

Even more simply, you can't rate games with a time handicap.

even a high rated player can have off days in there playing techniques so i would say yes its possiblefor a 1300 player to beat a 2700 player

One of Kasparov's great accomplishments was playing clock simuls against entire Olympiad teams and having plus scores.

Suggesting that such events should be rated is absurd though. The psychology and atmosphere of a simul is completely different from that of a serious tournament or match event.

That's a simple statement but doesn't explain why.

In order for a rating to have meaning, the playing conditions must be equal, Clavier.

Even when the playing conditions are equal other conditions must be met, such as time controls and so on. The Melody Amber events were equal but the blindfold tournament was unrated. The rapid chess was unrated for many years also.

Why is pretty obvious.

I once heard of a story of some guys that gave a GM free drinks just before a tournament, the GM still won. It looks that alchohol doesn't not interfer that much.

47, currently. 51 a month or so ago. http://ratings.fide.com/top.phtml?list=men

If you're +2700, you have a good shot at beating anyone in the world not named Carlsen. That includes the current world champion. Carlsen is currently making everyone U2800 look like a fish. It's incredible to watch!