Hi Lew - it was hard to tell from the picture of your room if it was a dedicated room and you could move speakers where you wanted to, and how much of a long rectangle shape it was. Yes its about positioning them 40-50% into the room about 6-9 inches from the side walls. They get left on a line using a technique where the bass response is smoothest and best.
You put your chair where the sweetspot is best.
I experimented with this technique and it did work well in long rectangular room where you are free to place the speakers wherever. But doesnt go good with the spouse in a shared room. cheers chris