Ahh, luck. The title in and of itself may seem a little confusing, because how can you track something that is, by human nature, mostly subjective and not objective? I will start off by immediately saying that there is no 100% definitive answer. In the end, everyone will have a differing opinion on if a team was unlucky or lucky over the course of 82 regular season games, because everyone views things a little differently. To that end, I do not claim to offer absolute, undeniable answers here.
However, there is some data out there that can make tracking luck somewhat more tangible.