My grade is much higher at 3+0 than 2+1

As the title says: My grade is much higher at 3+0 than 2+1:

3+0:  1292

2+1:  1044

Why do you suppose there would be such a difference?

I have over a 300 point difference between the two also, don't know why. My games are usually closer to 30 moves  so it is more like 2:30 but it is still close to 3 minutes.

Because a better class of players play 2 + 1?  Think it through.

That could be it, but it could also be because none of the strong players play that time limit. I think that was kind of the issue with the rapid ratings. They all clustered in the middle. That wouldn't explain a lower rated player having the same issue though.

I think that a 2|1 time control forces players to start out the first few moves at a faster pace since not enough seconds willl be added to give them extra time. Towards the endgame though, when there are less pieces on the board, the 1 second increments can sometimes help winning players avoid a loss on time.

I am poor at endgames. Therefore, my performance at 2|1 is worse than my performance at 3|0.

I'm glad to know it's not just me. I find it rather peculiar.

That is quite possible but since I am not very good at either and hence am playing other people who are also not that good, I'm not sure that's it.

That's a very good point about end games. I am poor at them too, and perhaps the 1 second increment prevents me from winning on time and so I lose more end games. I think you have a large part of the answer there, thank you.

I have a similar feeling when I play 2+1 unrated. I feel like I lose more often. I am quite good at endings but I think it's because I play fast but not very precise. So I win on time in 3+0 or 5+0 but will lose because of the add on

Thanks James, I am starting to realise that this is exactly my issue too. At 2+1 there is much more need to actually checkmate the opponent rather than simply play faster at the end. So, I think I need to work harder on my game and become a better player.

As long as each move is played within one second, and there are no lags whatsoever, there will not be a win on time by either player. 

Exactly, I think that's why I seem to perform better at 3+0.

Because in 3/0 you're more likely to win on time, even if you're losing on the board.

In 2/1, you're less likely to flag your opponent, due to the increment.

The 2/1 rating is a more accurate reflection of your playing strength.

If you want to become a stronger player, play more 2/1 (since it's your weakest format). Focus on winning games by way of checkmate, rather than the clock.

That all makes good sense. Thank you.

Having noted all our opinions, take note that 3|0 is under blitz classification on Chess.com whereas 2|1 is under bullet classification. Instead, 2|2 is under blitz classification.

Perhaps this could also be the reason why 3|0 is much more popular than 2|1 based on my personal observations.

I suspect you are correct there Eric.

In my opinion, 3 minute is faster than 2|1. I started playing 2|1 to have a good bullet rating. I only ever play 3|0 when I find it in the open challenges.