... the reason behind my earlier statement being...
If becoming adequate at something is all you can do before deferring to luck, then adequate is all someone will become.
Millions of people can drive the ball 300 yards, but none of them can beat Tiger heads up.
Millions of people can play the correct notes, but Beethoven can play better music.
Millions of people can karate-chop something, but Bruce Lee could karate-chop someone's head clean off.
There is artistry and true understanding of a subject that goes far beyond proficiency. To label it as "luck" is a copout, and a sign of laziness and ignorance.
To disprove Argotitan's earlier claim:
"Drano, I'm saying there are situations where multiple rational tactics exist. Logical deduction is not necessarily a one way thing when it comes to competitions.
[....] A principle is justified on its own merit."
Multiple rational tactics may exist for something as simple as a 1-on-1 board game where its a race to 18 dots. Many different tactics can help you achieve that modest goal. Now lets expand this to a real war (not modern industrialized, but old-school with hand-to-hand combat, equal numbers), Thousands more complexities dealing with mobility, geographical considerations, training, leadership, tactics, and the all important heart. If you were commander, could you now support your claim that multiple rational strategies have the EQUAL chance of success ('equal' being the key point of your claim)? Clearly, the victor would be the side which better accounts for and integrates all the complex elements, who knows how to exploit the other side, and knows which elements are greatest considerations to win the battle. Nothing in this case would be equal. Hence, your hastily labeled "principle" ("which stands on its own merit") is absolute hogwash (to borrow a term from RUFFHAUS' book). A principle is something that is true regardless of scale.
You are stretching this simple concept of skill into an argument that borders the philisophical debate of existentialism, determiniteness vs. free will, and all that other crap that people argue about for the sake of arguing. My point of view is simply that you are in charge of your own destiny, and if you try harder than the next person and do what is required to improve your skills of critical thinking, analysis, and synergy, then you in fact can become the best.