Are Luck and Favorable Variation the Same Thing?

Recently, I attended a conference at which there were several talks analyzing aspects of competitive games. In one of them, the speaker contended that the qualifying mechanisms for the PGA Tour were not very good -- particularly Q-school. His basic argument was, due to natural variations in golfers' scores, the limited number of rounds in Q-school, and the ratio of qualifiers to participants, there was a decent probability that some relatively weak golfers would make the Q-school cut at the expense of more deserving golfers. (He backed this up with a statistical analysis using empirical data.) I don't remember the exact figure, but I think he estimated about a 20% probability that Phil Mickelson would fail to make the final Q-school cut, which is quite high considering he's probably one of the top ten golfers in the entire world, let alone those trying to qualify for the PGA Tour.

In explaining his work, the speaker kept using some form of the word "luck", as in, "given a large number of golfers it's almost inevitable that some of them are going to get lucky and beat people who are better than them." About halfway through the talk somebody in the audience stopped him and said, "I don't buy your premise that this is luck. I've played a lot of golf and watched a lot of golf. You don't luck your way through multiple rounds, you have to outplay people, so I'm not buying it." A somewhat contentious, back-and-forth ensued, before the speaker conceded the point and said, "fine, we have a disagreement on the definition of luck, so I'll just use the term 'favorable variation', from now on." This seemed to placate the man in the audience.

It made me think. Are luck and favorable variation the same thing? As an example, consider poker, a game in which luck and skill are both large factors. There are two basic ways a poker player can beat a superior opponent. The first is they get really lucky, in the conventional sense of the word. Their opponent completely outplays them, but through total chance, they hit their cards and win (think flushes and full houses on the river). This is obviously not sustainable (see the law of large numbers or this Mark Knopfler title). The second way is that the inferior opponent experiences favorable variation. They outplay their opponent on that particular occasion. Maybe they notice an aberrant betting tendency by their opponent and exploit it, or maybe they are just "in the zone", and they make all the right reads, while their opponent makes the wrong reads. This is not sustainable either, because their opponent is better and eventually will adapt, and the tides will turn, but is this luck? On the one hand, you might say "no", it's skill, the usually inferior player just played better. There is nothing lucky about it. On the other hand, you might say "yes". It is a deviation from the expectation that favored the inferior player, and in this sense it's indistinguishable from the first scenario.Whatever the answer, it's an interesting question.