The Twelfth Man: A Tale of Old Shanghai Breakaleg Company Fringe Club January 25-27. LEAPING into the pot-pourri of a Fringe Festival can be a risky business for an amateur theatre company, especially when amazingly high standards have been set by overseas professionals. All the more credit, then, to the Breakaleg Company for providing a really enjoyable evening at the theatre with its splendid contribution to this year's Festival, The Twelfth Man: A Tale of Old Shanghai, a new play written by Piers Gray. At various times, the main action takes place at the bar of ''the Club'', or in the tiny office of a bookshop. The play is based - sometimes loosely, at other times closely - on events and people in Shanghai during the early 1930s. By giving some of his characters blatantly racist remarks to utter, the playwright is perhaps holding a mirror to reflect the same attitudes held by a number of British and other expatriates in Hongkong today. Into such an atmosphere comes Nigel who is young, British and obsessed with cricket - he works for BAT, the tobacco company. He is not very good at his job and is ignominiously ''sent up the river'' as a travelling salesman. His poor showing at work begins to affect his performance on the cricket field, where he sought refuge. Turning to books on cricket, he meets Agnes, a journalist who runs a bookshop and who is also involved in a Soviet spy ring. She persuades Nigel thathe hates his boss and others like him, and that there are people who would like him to work for them instead. Irony is an important feature in this play. Piers Gray, who also directs, drops occasional clues which point towards the outcome. Nigel says that he does not play poker, for example, since he is no good at bluffing. Cricket, a game once reserved for ''gentlemen'', is used with irony as a metaphor for a society in which only material success counts. The play is wonderfully whimsical and this aspect of it is picked up and echoed brilliantly by the very gifted Ralph Lister, who plays Nigel. He was absolutely ''top-hole'', as they used to say. Anita Szabo was also excellent as Agnes; here was a finely underplayed performance that was believable. Similarly, Abraham Lee was quite remarkable. He played the barman at ''the Club'', and another character who was involved in the spy ring with Agnes. He was particularly moving, without being sentimental, when he spoke of what it meant to be Chinese, and of his hopes for the future when China would be rid of ''General Chiang and his gangsters, the Japanese and their gangsters, and the Europeans and their gangsters.'' There must be a special mention, too, for John Tait, at the piano, who provided period music perfectly.