It's not all about scoring goals; convincing others of this is not easy but perhaps this will help.
Provided below is diagram to highlight a few key indicators on how the Opponent statistics averaged out, during three phases of the year, in penetrating the Timbers Defending Final Third.
When viewing the information provided note the Averages for Opponent Passing Accuracy and Passes Attempted, into the Timbers Defending Final Third, increased during the three separate phases of the year.
What's happening here is the Timbers are dropping their back four line a bit deeper; i.e. - allowing the opponent to penetrate a bit more.
In addition, with the back four playing a bit deeper the amount of time and space the opponent has when penetrating is reduced.
So - realistically, even with increased penetration, the reduced time and space afforded the opponent, should provide better opportunities to defend.
This defensive change didn't quite reduce Goals Against between Phase I and Phase II, to begin, but it did help generate more time and space for the Timbers in counter-attacking as the opponent was usually committing more players, deeper, in attack.
Overall, that additional time and space, in attack, saw the Timbers increase their Goals Scored from 1.03 per game to 1.93 per game.
It's only when the Timbers began to cede even more penetration to the opponent (Phase III) that they reached their best outputs this year.
Moving from 1.67 Goals Against, per game, to 1.27 while also increasing their Goals Scored, per game, from 1.93 to 2.09.
The Timbers are not the only team that took this approach in 2014.
When Jim Curtin replaced John Hackworth (after game 14) the Philadelphia Union statistics showed the same trends as well... the defense ceded more penetration but yet the average goals decreased by almost .5 per game while the points earned, per game, increased.
To view that article (read here).
So when Caleb Porter indicates the Timbers got better in defending he's spot on.
What was missed, by some, is that the early season bump in wins (games 9-23) did not also result in a decreased goals against; in other words the defense didn't really get better.
But when they opened up even more, they did get better - on both sides of the pitch.
Defense wins games...