This skilful left-arm orthodox spinner, who made his first-class debut in 2012, is one of the major contributors in keeping Somerset in the first division of the English County Championship. After putting in some notable performances for three years, the left-arm spinner’s most prominent County Championship season came in 2016 when he took 68 wickets at an average of 22.58. Shockingly, later that year, his career suffered a big dent when his action was found to be illegal. However, the Somerset spinner showed great determination and mental strength as he underwent remedial work on his arm and body position, re-modelled his action, rectified the problem and then finished the 2017 season with 51 wickets.

In early 2018 while playing for the England Lions against West Indies A, the left-arm spinner achieved match figures of 8-110. Jack knocked hard on the doors of the English selectors with that performance. His hard work finally paid dividends when he got picked in England's Test squad for the tour of New Zealand, as an injury replacement for Mason Crane. He made his debut in the second Test in Christchurch and performed decently, taking two wickets.