Is there a rational explanation for this?

[iceman5]

My last 20K hands at Prima $1/$2NL
$60/hr playing 3 tables...16.5BB/100 hands

My last 10K hands at Party $1/$2NL
$18/hr playing 3 tables....5.0BB/100 hands

Win rates are true win rates (double PT stats)

Im stumped and frustrated. Obviously I can just keep playing at Prima, but there has to be an explanation. Maybe Im playing differently, but I dont see how or why I would be.

The only difference I see is that Prima allows short stacks. There is a $20 min buy in on a $200 table. There are always several short stack around $30-$100 and they almost always stink and donate their money.

That cant be enough to make this big a difference can it?

On the other hand, my $2/$4NL win rate at Party is quite a bit higher than my $1/$2 win rate at Party so maybe its just been a lot of bad beats while playing $1/$2?