[2][3] He was one of four sons of Walter Ramsay Allan, an Edinburgh general practitioner, and Elizabeth Brownlee (née Moffat) who had studied at Oxford University and was described as "a classical scholar".
On debut he returned figures of one wicket for no runs from seven maiden overs, five of which were bowled to Len Hutton, one of England's leading batsmen.
[5] After his Oxford team-mate Colin Cowdrey recommended him to Kent's committee, Allan made his county debut during the 1954 summer vacation, scoring 1,000 runs during the season.
[a][1][3][8] He was selected to tour Pakistan with an MCC side in 1955–56, but forced to decline due to university exams; his place was taken by Tony Lock.
[7] Although not the hardest spiner of the ball, he used flight and bowled an "immaculate length"[8] to defeat batsmen,[7] and was an accurate and reliable bowler.
[12] Allan Massie describes him as "one of the best Scottish cricketers of his generation, and indeed more than that";[8] his Ayr team-mate Keith Graham described him as "one of the shrewdest left-arm bowlers" he had seen,[9] and he was compared to the likes of association footballers Denis Law and Jim Baxter in terms of his importance to Scottish cricket.
[1] He scored 4,988 first-class runs and made five hundreds, including two in one match for Kent against Northants in 1955, his most successful season with the bat.