This is what it comes down to in investing -- being right just a bit more often than being wrong, and when we're right, pressing our advantage. Easy in theory, but extremely complex and nuanced in practice.
A big point that many professional traders emphasize is that the greater your advantage (and we're talking in basis points here, realistically - 5+ bps - against your opponents), the more you need to press. Even Charlie Munger will tell you that when an opportunity comes along, you need to put as much weight behind that trade as possible. (See #6 from the following list of his rules for investment success, about asset allocation.)
Ask John Paulson.