I have two issues with using GA as a tiebreaker before GD(x). First, using a limited GD score such as GD3 helps to eliminate the effects of "outlying" games. For example, if a team's keeper is injured or absent for one game and it happens to be against a strong opponent, you could rack up one heck of a GA score in one game, but it wouldn't be representative of the team's overall ability through the course of the season. GD3 or a similar limitation reduces the effects of any atypical, outlying games. Sure, you can possibly be the team who scores the most and gives up the fewest and still not finish first under GD3, but if you gain that record by racking up goals on an atypically disadvantaged team, does that really make you deserving of the playoff berth over someone who called off the dogs, or someone who gave a second or third-string defender or keeper a chance after victory was assured, and as a result gave up a goal or two after scoring a safe lead?
Which brings me to my second issue...do we really want to make a shutout "vital"? Do we want to make the game in all of its intricacies and facets boil down to simply defense? What does that accomplish for the game? Is it more exciting for the fans, developmental for the entire field of players, and representative of a team's total strength to get a small lead and then bunker down on defense to preserve the shutout, or to take some risks, play the whole field, and play a balanced game, even at the risk of possibly giving up a goal? If GA is a first tiebreaker after head to head, does a 1-0 victory really indicate a stronger team than an 8-1 win?
Don't get me wrong; I respect and value a good defense. A good defense can buy the offense the time and opportunity to win games. I just don't think the shutout is the be-all, end-all of a good soccer game, and remember, whatever we set up as the criteria for playoff placement, eventually, that's what the priority of the games will become. Goal differential, within prescribed limits, will reward teams for wins, reward them more for decisive wins, reward the losing team for keeping it close, and with the limits, will reduce the incentive of stronger teams to run up a score to pad the gap.
