I hope others will check my numbers here, as it's a bit complicated and needs some confirmation.

What I'm really trying to do with several of these posts is arrive at something like the Sklansky groups for Omaha, although there are also several additional factors to bear in mind--just one example: 4567 is imo EXTREMELY strong in any multi-way pot (raised or not, but the more the merrier) but much weaker HU. By constrast, 3-legged dogs are quite weak multi-way, but actually pretty strong HU or 3-way. Also, crappy AA or KK hands gain a lot if it's short-handed, since the overpair has significant value. Anyhow, my current work toward groupings is more directed toward multi-way pots for the moment.

If anyone has any cross-references or would like to check up on the following (I can provide more details if needed), then please let me know!

First, I got my numbers a little more exact on full wraps, taking 5678 as my example.

I count 532 flops (out of 17,296) where you flop the nut straight with that hand. That makes 3.1% of all flops. On all of these, you have either 4 (filling up) or 6 (bigger straight) outs to improve.

I also count 1,344 flops where you have 11 or 13 outs to the nuts (ignoring suits on all of this). That's another 7.8%

Ok, now taking this full wrap as starting point, I decided to compare a wrap with a hole at the bottom, which I was considering to be the strongest of the 1-gappers.

On 4678, you hit the nut straight on 2.9% of flops (very little difference), but quite a few (roughly 30%) of those give you no chance of improving.

On the same hand, you have at least 11 outs on 7.2% of all boards (compared to 7.6% for the full wrap), but you also gain a 16-outer (namely 359), which you don't have on the full wrap.

I'm going to conclude that these hands are only very slightly worse than full wraps.

I'm not completely done yet with my sample wrap with a hole at the top (4568), but I do have the made str8 flops for it.

There, you make your nut straight on 2.6% of all boards. Interestingly, though, your chances of improving are actually a little BETTER with this hand than with the hole at the bottom.