"Luck" is showing up consistently so that you're present whenever opportunity decides to show up. Thus, you make your luck. And I believe this is where the resilience mentioned in the essay comes in; to ensure you always show up.
One of the most interesting investigations into luck was last year's show The Experiments: The Secret of Luck, by Derren Brown. The entire episode is avaiable on YouTube here:
http://www.youtube.com/watch?v=O4mN33w5Ftw
I would heartily recommend anyone watch it, it certainly enhanced my own understanding of the concept.
