Luck, by and large, controls the output of any game. It all averages out over time, and skill and strategy show in your long term results.
Luck also works different ways for different people.
For good players with real strategies, it is bad luck which causes them to lose more than any, because they have a plan and strategy, and good luck may benefit them a little, but their strategy would have given them a win anyways.
For poorer players, with less skill. luck often helps push them to victory. As without it they do not have alot of a chance going up against someone better skilled at strategy and gameplay.
All in all, I believe luck plays a part in every game, more so in some than others. but the definition of strategy in this game would be your ability to plan around, and cope with, whatever kind of luck you have, so in the long run it is always strategy and skills that win a game,
No matter how bad your luck went, there was always someone somewhere who could have gotten the win in your situation.