What is the origin of the idiom "on a roll" and when to use it?
The idiom "on a roll" is thought to have originated in the 19th century. It is believed to be a reference to the fact that a rolling ball is difficult to stop. In other words, when someone is "on a roll," they are doing well and are likely to continue to do well. The idiom is often used to describe someone who is successful or who is doing well in a particular area.