OK, I understand what it is but at times I really question what its calculating.  Just last session I finished moderately up in winnings but pretty big down in All in EV.  I know I was playing very well regarding all in spots looking at the cards going in, despite a set over set cooler in 3bet pot.  When I checked my HUD after all my all ins were between 60 to 88 yet I it said I was down -80+.  I really don't understand it.   Anyone has any info on this?