Skewed common sense -- dynamic court (part 2)

Remember the last post, we introduced the random expansion/contraction? Here's the extension to it.

Type 3a -- simple random expansion/contraction
Think about this in terms of the cartesian plane, with the middle of the goalpost as the origin and the width of the court (the one along the goalpost) as the x-axis. In this expansion/contraction, the width of the court would expand/contract evenly on the positive and negative end, such that the two distances from each end of the court to the origin are equal.
This may prove to be easier for the keeper, since the center position is the same for all possible goal sizes.

Type 3b -- complex random expansion/contraction
Using the same cartesian plane, with the center of the goalpost as the origin, this expansion/contraction is slightly more complicated. Similar to Type 3a, the expansion/contraction only occur along the x-axis. However the expansion/contraction does not need to result in two equal distances from each end to the origin. I.e. The center of the goalpost/court may no longer be at the origin after expansion/contraction.
This would mean that the keeper would have to move around to remain in the center position with regard to the court and the goalpost. Good luck, keeper!