The reason the triangle is the strongest of the polygonal shapes is because, when force is added to a triangle, that force is spread evenly throughout all three sides.
This is the same logic Eric Smith applies to The Winning Edge Way: An Athlete and Coach's Guide to Becoming a 3-Dimensional Competitor.
As complex and nuanced as team sports are, there are three main components at their core: the player, the team, the game - each reliant on the other. In this guide, Smith meticulously breaks down and examines each of these three components through the lens of his own personal experience as both athlete and coach.
One should devote oneself to a purpose not for the purpose but for that which can be learned and gained along the way, to then be passed along to the next generation. And when you devote yourself to a sport (or purpose), as Smith has, you learn a thing or two - or in this case, three!