 Complete the following phrase:  Until the mid-1960s, the goalposts were similar in design to rugby posts, with the cross-bar and uprights supported by stanchions installed directly underneath the uprights in the shape of the letter H. A transitional design from this time retained the twin set of stanchions but placed them behind the cross-bar. In this design, the cross-bar and uprights were supported by a set of horizontal, vertical and diagonal stanchions behind each upright. This design was last used professionally in 