From 1920 to 1938, Hirst was the cricket coach at Eton. The college's most important match was the annual match against Harrow at Lord's, and during Hirst's tenure, the team were unbeaten in the fixture, winning the six matches that produced a definite result and drawing the remainder. Following Hirst's retirement, Eton lost to Harrow in 1939 for the first time since the First World War. In the period of Hirst's coaching, Eton only lost once—in 1920—to Winchester. A combination of Hirst's technical knowledge, playing experience and empathy with young people made him a very successful coach. He taught technical proficiency, but encouraged his pupils to play their natural game. His "Times" obituary noted "his professional capacity earned him the respect of the boys and his natural good humour and good manners gained him the love of all." When he retired, a dinner was held in his honour at Eton.