First, I liked kuso's term of VPIP of 25%-35% as "sweet spot" for Omaha.
But I've been adding up various playable hands, being fairly liberal with holey wraps and still have trouble coming up even with 25%. I think this is a bit of a leak under limpy conditions (in a raisy game, I don't have a problem going down quite a bit--like 20% for limps and 15% or less for actual raised pots).
So, while I'd like to have enough "playable hands" to put together 35% under some conditions, I just don't see where they're coming from.
As bare pairs, JJ-AA have been consistently profitable for me. 99-TT marginal (right around break even). I was playing them even with bad side cards for a limp for a while. Then when I noticed how marginal they were, tightened it up so that I only played them with something extra (either wrappy or with suited A). I think that should put them in the actual "profitable" category, which is certainly what one wants.
Then if you take a fairly liberal smattering of wraps, those make up about 7.5% of all hands. Add that to the 2.5% each for JJ-AA and you get 17.5% or thereabouts.
Then there are several semi-unusual hands that are good but don't make up big percentages (pair wraps, suited A wraps even with a hole, 2 pair like 6655). Those get you to somewhere between 20% and 25%, and I think all of those can be played profitably.
Now, it would also be possible to throw in ANY 4 distinct cards ds, as I did for a little while (during my losing streak, I might add), but a lot of these are pretty crappy and give you very little on draws to the nuts. You just have two bad flushes, maybe with some random straight outs. ALL ds hands with 4 distinct cards make up just short of 10%, so that would get us above 30% (despite the fact that I'm double-counting the ds wraps).
Anyhow, I guess it's possible to throw in just any 99 or TT. It would be difficult to find out exactly why they were marginal (anyone else have different results on these?), but if they just ARE marginal with nothing else going for them, it seems a bit pointless to play them.
So, here's another group that I tried for a while and didn't really like, but maybe it has some value: Any (or at least almost any) ss A with 4 distinct cards. That's at least a draw to the nuts if you get your flush draw, and (in contrast to HE), the additional side cards are going to add SOME value.
Anyhow, I'm not quite at the point where I'm willing to play just ANY suited A, but I think being pretty liberal with them (i.e., if the side cards have almost anything going for them) might be worth trying. I think these also make up something like 7% of all hands, but it could be a little more.
So, I guess my question to those who play 25% or more of hands is this: Where are those extra hands actually coming from? I just can't seem to find enough of them that have any real potential, hence, seems a bit pointless to play them.