Yes, it's true that you chuck the original mother plants after a year or two of fruit and let the plants from the runners become the new mother plants. Train their runners back into the area where the original plants were. Crop the first set of runners for a year or two, chuck them when the next set of runners is ready to fruit and so on. If you start with widely spaced rows and train the runners into the center, it's easier to dig out the mother plants and create new rows for the next set of runners to be trained into. I'm not sure if I described that well but hopefully you can see that there is a pattern of replacing mothers with runners back and forth across the garden every couple of years.