Hey, I was just checking this series out for fun. I liked the first video and learned quite a bit from it. I'm not a PLO player so I may have made a mistake here, but I think some of the info about the high gap versus low gap (e.g. 8764 vs. 8654) is inaccurate. I know there was an error in the video but I think the correction in this thread is still wrong.
Imagine x is a non-relevant card (not necessarily a low card - it's actually easier for x to be a K although you'd really rather have it be a 2 on the T9x flop).
8764
53x: 13 outs (four 2's, three 4's, three 6's, three 7's), 13 outs to the nuts
54x: 13 outs (four 3's, three 6's, three 7's, three 8's), 13 outs to the nuts
65x: 17 outs (four 3's, three 4's, three 7's, three 8's, four 9's), 11 outs to the nuts (the 3's, 4's, 9's)
75x: 17 outs (four 3's, three 4's, three 6's, three 8's, four 9's), 11 outs to the nuts (the 3's, 4's, 9's)
85x: 13 outs (three 4's, three 6's, three 7's, four 9's), 7 outs to the nuts (4's, 9's)
T9x: 13 outs (three6's, three 7's, three 8's, four J's), 3 outs to the nuts (6's)
8654
32x: 13 outs (four A's, three 4's, three 5's, three 6's), 13 outs to the nuts
74x: 13 outs (four 3's, three 5's, three 6's, three 8's), 13 outs to the nuts
75x: 17 outs (four 3's, three 4's, three 6's, three 8's four 9's), 11 outs to the nuts (3's, 4's, 9's)
76x: 17 outs (four 3's, three 4's, three 5's, three 8's, four 9's), 7 outs to the nuts (3's, 4's)
87x: 13 outs (three 4's, three 5's, three 6's, four 9's), 3 outs to the nuts (4's)
97x: 13 outs (three 5's, three 6's, three 8's, four T's), 3 outs to the nuts (5's)
In total each hand has 86 outs. However, 8764 has 58 nut outs (~67% of the outs), while 8654 has only 50 (~58% of the outs). So the difference in hand values is actually much greater than what was posted in this thread. From looking at the above scenarios it's clear that the hand with the higher gap loses value more quickly as the flop cards get higher.
This doesn't take into account other flops that may be favorable. Since I'm not a PLO player I don't know what these are, but I suspect that top two + a straight draw is good. In that case it should be intuitive that the hand with higher cards (i.e. lower gap) will yield stronger combo made hands + draws.
And I think Vanessa's point about not getting re-drawn is very relevant. From looking at the starting cards and flops above I think it's pretty clear that when you hit a draw on the turn your hand will be more likely to hold up when you have 8764.
