Both situations apply to poker I believe.
When you know the math and you can do the numbers right on your head you are able to calculate your
odds and how many outs you have, if there is a high chance I always go for it.
Lucky comes to the players that know how to read a poker hand/table, also paying attention to the other players is a factor, even in online games you can see the ones who like to steal a lot of hands and the ones that only play huge hands like JJ and above...
Overall I trust more the math then skill, to help i have a calc beside me, the rest is reading the players and their bets