Hey pdfbq,
If you play traditionally strong ranges, you will generally run below Ev. This is mainly because you gain a little on your net expected line when your hand wins and the line goes down significantly when you lose.
To use a simplistic version, say you are in the BB with AA with 100 BBs and villain is in SB with 100 BBs with KK. Villain shoves, you call and there is now 200 BBs in the pot.
You have 81.26% equity.
So your Net Expected BBs is 200 BB s * 81.26% = 162.52 BBs. When you win, your Net Expected line will rise by 37.48 BBs while if you lose, your line will go down by 162.52 BBs.
Suckouts, coolers and bad beats have a devastating effect on your Net Expected line and unless you are doing the same to your opponents, you will always run below Net Expected.
This is OK and the majority of tournament players will have this problem. It is much more important to keep the green line as far above zero as possible.
Hope this helps
Laz