This is the kind of “scoring” stuff I don’t typically care much about, because it’s handicapping, and we all know real golf is played without handicaps. (I’m only being a bit serious there…).
Higher handicappers are generally favored in Stableford games (I’ll get into reasons later) and are more so when the points escalate non-linearly.
They’re favored for three reasons. Or two, depending on how you count them.
The first is easy: there are often more of them. This one’s so obvious we’ll mostly skip it. Also I have no idea what the distribution of handicaps at the NIT was. You might count this as half of a reason.
Second, they’re favored simply because their odds of shooting below their index by enough to earn more points is more likely than a low handicapper doing so. The old “Odds of an Exceptional Tournament Score” chart showed, for example, that the odds of a 5.9 or less handicapper shooting a differential that is 5 to 5.9 below his index is 1:379. For a 13.0-21.9 that’s 1:174, and for 22.0 to 30.9 it’s 1:72. The 13.0-21.9 shoots 7.0 to 7.9 below his index roughly once every 552 rounds, and 6.0 to 6.9 below one in 323 rounds (still lower than the 1:379).
The third reason is that this advantage (the other half-reason) is that many stableford games aren’t played linearly, and the higher handicapper has more variance in their hole-by-hole scores, and the “bad” scores (the net bogeys and doubles) don’t add up fast, the net birdies and eagles do. In other words, a scratch golfer will often have a ton of pars, while the higher handicapper will have fewer pars but more net birdies and bogeys. If the system is 1-2-3, the 1-3 holes of the higher handicapper cancel the 2-2 holes of the scratch golfer, but if it’s 1-2-4 or something, that’s a few more “1-4” pairs of holes for the higher handicapper on some 2-2 pairs for the scratch golfer.
As for the NIT, and the quota game, the tendency is to think that it favors the lower handicappers because higher handicappers make a lot of doubles+ and thus don’t get points, but consider linear stableford versus linear quota: they end up the same. A scratch golfer who makes 18 pars (or a bogey for every birdie) earns 36 points in both games (in quota, finishing at 0). A bogey golfer (18 handicapper) who makes 9 doubles and 9 pars (or net bogeys and net birdies) finishes with the same count: 0 in quota, 36 in stableford.
So that leaves the second reason as the primary advantage in either game - the higher variance in a higher handicapper’s game.
(This is all just the math perspective. It says nothing of course conditions, etc. Sometimes, for example, higher handicappers fare better in bad wind because their balls don’t travel as far in the air and don’t get knocked offline as much. A 130-yard thinned 7I goes about 127 yards into a stiff breeze, while a 170-yard 7I might go 140 or 150 or 160 into a breeze. You guys also had ridiculous hole locations from what I gather, etc. The margins above are pretty small, and if you factor the distribution of handicaps, you could arrive at all sorts of conclusions about which groups were favored slightly.)