have a clue

"It was such a nice, welcoming way to get into the sport, as someone who didn't have a clue how it worked when I started."

Asked about that finding, Welby said: "You can believe it or not, I did not have a clue."

“He doesn’t really have a clue how California water systems work,” Gleick said.

“He doesn’t really have a clue how California water systems work. If he cared about California water, which he doesn’t really, he would pay attention to climate change.”

When she interviews members of the public at the matches, "some of them are very knowledgeable on the sport, and some of them absolutely don't have a clue and couldn't name three players," she says.