Zero-sum "games" and Critical Mass

In both my studies and recreation I have often come across a universal question of life: for any given situation where there is a declared 'winner', why did that person or group win? This becomes an especially crucial question because some "games" are played for all the beans; most notably war and politics.
History books are the common venue for learning about these subjects and yet they are often merely a showcase of winners. Historians generally start with the victorious conclusion and then research backwards to find its causes. However, in doing so they can critically misrepresent the rules of such zero-sum games, which appear pre-destined in retrospect but are usually not at all.
Rather, they are an exercise in building critical mass. From presidential campaigns to military ones, the race to critical mass is the story of humanity's most epic struggles. The pivots of history turn at the point when some outcome or string of events convince a sufficient plurality of people that one side is winning. From that point the greater majority will seek to gain benefit by aligning themselves to the perceived winner, which in turn reinforces their lead status.
Therefore the first question "Why do I want to play this game?" is closely followed by "What are the rules?" and "What are the possible strategies for reaching critical mass?"