Ah, right. That's a shame. Seems such a pointless thing to do really.
Players much better than their ratings

I highly doubt that any significant portion of players are sandbaggers.
More likely a change in the rating system, they lowered the bullet ratings, maybe something similar with blitz.

I don't remember thinking anyone was letting me win in live (or if they did I didn't cooperate!) or resigning early for no reason.

I tend to agree with you scottrf that it seems unlikely. I have sometimes thought someone may be cheating, but reviewing the games generally I have just played some awful moves.
However, I just did a quick look and found 3 of the last 10 players I played were 290 or more below their peak (for me that would only be when I signed up 18 months ago, and then only for a couple of games). Another 4 were 190 or more below their peak. Most of these peaks were in the past six months.
I only played once (ages ago) when I was sure it was a sandbagger, who was rated about 800 and had peaked at 1700. It would also be an easy thing for chess.com to spot I'd think. Still, makes you wonder.

They probably just had off days. I can play at ~1800 on nice days, or ~1500 if I'm not focused.. It's easy to play 200-300 points below your actual strength when you're tired/unfocused/preoccupied/not caring. I've played 1600s who peaked at 1900 (who lost either on time or hanging pieces, but they were outplaying me.)
One notable guy was rated exactly 100. No, I didn't leave out a digit. He peaked at 1900+, I offered a challenge for the experience... and got crushed.

Yes, I agree that anyone can have an off day, or even an off period (I have lost a dozen times in a row before now, to often mediocre opponents) but I thought that, in general, ratings would be more stable than that. Still, I think now I was probably wrong. Hope so anyway.

I don't remember thinking anyone was letting me win in live (or if they did I didn't cooperate!) or resigning early for no reason.
I don't remember that either. But when I look at the profile of surprisingly strong 1200-1300 Blitz players I regularly see they have many lost games they resigned on move 0 or 1 (didn't even know that was possible, I thought you only could abort the first couple of moves, but it happens). And their rating fluctuates between 1200 and 1500 all the time. Their real strength is way beyond 1500 of course. This makes a typical sandbagger profile I would say.
One time I asked such a player about it, and he actually admitted it (sort of, he explained that his little brother played on his account and lost all those games).
I've been all over the shop. My blitz rating has been as high as 1680 (way back in 2009), but is currently 1414. Its been as low as the low 1300s, tends to fluctuate when I've been away for a while or on a losing streak; I tend to place myself in roughly the 1400s as that's where I seem to find myself the most.

Because at a certain level it is more likely everyone can lose or win against each other. You see this in OTB tournaments aswell. I am speaking of the rating bracket 1300-1800.

Probably because most people below 1800 still tend to blunder, so our matches can end in huge upsets fairly frequently. Who blunders first, who blunders back, etc.

Sandbaggers! That's a funny word!
''I have no hard statistical evidence, but I think there are some folks who will sandbag their games so they can get into lower rated tournaments and win some silly trophies.''
How stubit is that?!

The numbers don't make sense either. 7/10 are a fair amount lower than their highest rating, and the reason is supposed to be people who are trying to get a low rating to win trophies.
Even with we are to believe that many people are sad enough to, I don't even think such a high proportion play the live tournaments.

Thanks Panic_Puppet; I know it's possible to fluctuate quite a bit, but looking at your rating now it's still only 260 below a peak of four years ago which doesn't seem unreasonable. 3 of 10 players recently for me had 290+ differences within the last few months, 7 out of 10 had 190 or more differences. I might expect a gentle downward trend for some players, but surely a gentle upward trend, or a levelling out would be more likely and that doesn't seem to be the case in general.
For myself, I don't care that much if I am playing players higher than their grade might suggest, but I do check for my own sanity if I am trounced by a 1300 player. Sure it happens now and then, but I can quite often drop a piece these days (and all too frequently do) and still beat a 'real' 1300 at Blitz. You do get a feel for the kind of moves people play at certain grades after a while.

A good way to keep your blitz rating from fluctuating so much is to play higher rated opponents (+50 for the low and say +300 for the high). If you lose a game, you don't lose as many points and winning is the opposite. It's strange, but the higher rated opponents in 5/2 blitz aren't playing that much better. However, they are usually very good at time management.

A good way to keep your blitz rating from fluctuating so much is to play higher rated opponents (+50 for the low and say +300 for the high). If you lose a game, you don't lose as many points and winning is the opposite. It's strange, but the higher rated opponents in 5/2 blitz aren't playing that much better. However, they are usually very good at time management.
I just don't get my seeks accepted when I try that.

The faster the time control, the wider the possible rating fluctuation. Especially when you are playing continuously for too long a time.
"Addiction" can hurt your rating, big time. A 150 point rating fluctuation (in either direction) is hardly unusual.
If you've been drinking (too much), or playing for 4 hours straight, a 200 to 300 point fluctuation is not unusual.
Sandbaggers and engine users, notwithstanding.

For my own two cents, I have an absolutely ridiculous live standard rating. Despite the fact that I'm getting stronger, it keeps going in a negative direction. This is for two reasons:
1. They are in-group tournament games where almost everyone is rated higher than me
2. I have a HUGE problem with nerves in said tournaments. My nerves get the best of me, I screw up, blunder and then resign. Happens almost every time. I can't run from it though.. I have to get on that horse and try again. One of these days, I'll win. ;).

I guess that's true zborg. I tend to duck out if I lose a few games in a row, as I know it's likely to continue; it can even go on for a day or two.
I have sometimes felt that "I'll win the next one if it's the last thing I do" feeling, but I know it's not healthy so I try and go and do something more productive. Probably if there's nothing pulling you away it is possible to carry on losing like an addicted gambler, and then yes, you could lose a lot of rating points. Still 300 points probably equates to around 40 losses to similar players; still quite a lot.
I play quite a lot of blitz games, mainly because I seldom have big chunks of time to play longer games, though they are more enjoyable when I get the time.
Quite often I am playing players rated 1300-1350, and they are really good. Then I check their record and find that they have quite recently been rated 1600-1700 or higher at Blitz and have played thousands of games.
I average around 1500 but do drop down to 1400 or below occasionally, but dropping 300-400 points seems a bit weird. I am aware of the term sandbagging, but didn't expect it to be that prevalent. Am I missing something here or are some players ratings just naturally that volatile? I don't mind that much, as ratings are not as important as a good game anyway, but it seems a bit odd to me, and it's not much fun on the odd occasion playing people way better than me.