In terms of bowling, Kilner was an effective performer on rain affected pitches. His accuracy also enabled him to bowl on good pitches without the batsmen being able to score too many runs. In 1923, journalist Alfred Pullin said Kilner spun the ball more than any other English bowler. He noted, as did "Wisden", how Kilner often bowled over the wicket, meaning he bowled from the right hand side of the wickets, unusual for a left-arm spinner in this period. This established a contrast with his fellow left-arm spinner, Wilfred Rhodes, and increased their effectiveness. Furthermore, it allowed him to surprise batsmen with a different delivery, such as one which did not turn. Kilner's "Wisden" portrait also credited him with the gift of imagination, describing how he always tried to think of new ways to beat and dismiss batsmen. He would experiment with his bowling, for example altering his pace slightly, if conditions were unfavourable towards bowlers. Kilner delivered left-arm wrist spin at times, constantly practising it in the cricket nets. His brother Norman believed Roy was the person who coined the term "chinaman" to describe such a style, although other players have also claimed to originate the phrase.