I took 2 of the 15' long strips and soldered them together. I then took the other two 15 footers and soldered them together to make a pair of separate but matching 30' runs.
Hopefully that makes sense so far.
Now, starting in one corner of the pool, both 30 foot sections get their power. One line goes left down the long run and across the back where it ends in the opposite corner from where it starts. The other line does the same thing on the other two sides of the pool. So, for lack of a better term the heads start off in the same corner together and the "butts" meet in the opposite corner so there's uniform brightness throughout.
If that still doesn't make sense let me know and I can put up a diagram.