Former Liverpool defender Steve Nicol has questioned the value of the club's throw-in coach Thomas Gronnemark.
Reds boss Jurgen Klopp added the Dane to his staff last year.
But Nicol, after the Reds' win at Wolves, said: “It just annoys me when people turn around and say clearly they worked on that in training.
“I would love at the end of the year if the throwing coach looks at all the throws to see which ones worked and which ones didn't.
“We are never going to know that because football is all about a player seeing something and making a decision. A large part of football is what goes on in a footballer's brain."
This season Jurgen Klopp's side have a 68% ball retention on throw-ins compared to 48% for the rest of the league. That is the second highest in Europe, just behind Danish side FC Midtjylland.