Absolutely - luck is the most important thing! I can always put you in a tough spot requiring you to make a tough decision, but if right after you make the absolute wrong decision you hit the 2 outer, well, there's no other way to put it.
I have the same skill set day-to-day, which isn't actually too bad, but some days it all works better than I ever could have possibly imagined (sorry Trump) and other days it falls flat. I know when I'm having a lucky day and I know when I'm not. It's kind of like night and day. I also know when I'm playing poorly and whatever happens to me has nothing to do with luck and everything to do with my playing badly that day.
I mean - it's very clear, very transparent. All else equal, the only difference day-to-day is the luck, good or bad.
The most important skill I have is knowing when to quit - either because I'm playing poorly, or because I'm out gunned, or because I'm unlucky that day.