The position around move 14 illustrates the importance of positional factors and ease of play, especially at the Class level. White does not have a significant advantage, but the advantages he does have (the two bishops, open diagonals, more queenside space) make the game much easier to play. All it takes for Black to lose is one bad idea - the slow transfer of his queen to the kingside - and White is able to shift to tactical play, taking advantage of Black's light-square weaknesses to slash open the position. Black in response stakes everything on an unprepared kingside attack, which fizzles when I carefully calculate to a safe (and winning) position.
While my opening play here was not necessarily optimal, it got me to a comfortable middlegame position with latent threats and easy play. After that, it was simply a matter of recognizing opportunities in the position and keeping mentally focused. Overall, this was a good example of how your positional advantages can be turned into concrete ones, after your opponent ignores them and simply tries to execute his own plan.