Approximately four minutes of quick-fire specialist and general knowledge questioning confronts four doughty contenders for this year's Mastermind title.

Memory, clarity, concentration, tactics, and nerve are all required in this formidable challenge to the intellect.

Tonight's contenders are: DENNIS BIRD, Civil Servant

JACQUELINE PEARSON , postgraduate student

MICHAEL MUNN , lorry driver

MARTIN CABOURN SMITH , Chartered Accountant

This second heat brings together contestants who between them have a wide variety of talent.

As they grapple with the answers to questions both specialist and general knowledge, they will require all their mental faculties to be ticking over in top gear in this quest for the title Mastermind 1975. Tonight's contenders are:

DOROTHY F. BUSHELL , unemployed RICHARD J. EVERETT , schoolmaster MARGARET ASKEW , journalist ARTHUR GERARD, retired

Nottingham University provides the setting for tonight's ' Battle of the Polymaths.'

The occupations represented are as diverse as the specialist subjects that have been chosen.

Tonight's contenders are: CLIFFORD WARNER, Local Government Officer

JENNIFER SMALLMAN, librarian REV JOHN GIBSON , priest JOHN HART , schoolmaster

An American at Oxford University, a Miner, a Chartered Surveyor and a Systems Analyst make up the group who are in contention tonight for the Mastermind title. They are:

RICHARD CARDEN, Systems Analyst JACK TOMLINSON, Miner

VICTOR SIDE, Chartered Surveyor STEVEN SCHNEEBAUM, Student

Introduced by Magnus Magnusson from Sheffield University Tonight's contenders are: MARTIN MCCLELLAND, sheetmetal worker

GEORGE BULL, solicitor

PAULINE FOWLING, teacher

KENNETH BURTON, railway clerk

From which town will tonight's winner emerge?

This group of would-be 'Master-minds' come from Northwich, Southport, Liverpaol and Wallasey. Tonight's contenders are:

CECIL CRILL, retired Naval Officer JEAN HANDLEY, teacher RONALD MCGOWAN, Inspector of Taxes

NOEL FAGAN, unemployed

Bath University provides the forum tonight for four more hopeful ' Masterminds.'

Tonight's contenders are:

FRANCIS HOWE, schoolmaster IVOR JEFFERY-MACHIN, Anglican priest

GLYN COURT, teacher

JAMES COATES, retired bank official

So far the preceding seven heats of Mastermind have been won by the men.

Will the lone woman in tonight's group from Wales win through to the Semi-finals?

Tonight's contenders are:

RICHARD DALE, schoolmaster GENA DAVIES, unemployed VISCOUNT DAVID TENBY, Member of House of Lords

ANTONY CARR, university lecturer

The venue for tonight's heat is the Open University at Milton Keynes.

Tonight's contenders are:

PHILIP SKOTTOWE, Barrister GEORGE EARNSHAW, Lecturer JENNY JOHNSON, Histopathologist DAVID BURNS, Local Government Officer

This 11th heat comes from Scotland's ancient seat of learning, St Andrew 's University.

Tonight's contestants are:

KATHERINE WATT, retired teacher

JAMES MURRAY, retired headmaster FRANCIS LAMBERT, lecturer IAN SMYTH , schoolteacher

From St Andrews University, Scotland, contestants from Northern Ireland, Southern Ireland, and Scotland battle for a place in the semi-final round.

Tonight's contestants are: ALAN BLACKBURN, student ARNOLD O'HARA, teacher

TIMOTHY PAXTON, schoolmaster

GEORGE JOHNSTON, schoolmaster

Manchester University provides the venue for this semi-final, the first of four, one of which is reserved for the four best runners-up.

Tonight's semi-finalists and their special subjects are:

STEVEN SCHNEEBAUM, law student, United States Constitution JOHN HART, schoolmaster, Rome and Romans: 1st Century BC MARTIN MCCLELLAND, sheet-metal worker, British Military Campaigns: 1700-1815

DAVID BURNS, Local Government officer, Life and Reign of Richard III

The winner of this match will go forward into the final.

Tonight's Semi-finalists are from Bournemouth, Wallasey, Bangor (Wales), and Glasgow. They are:

IVOR JEFFERY-MACHIN, Anglican Priest, Dutch 17th-century painting

NOEL FAGAN, former sales manager, The two World Wars, 1914-18 and 1939-45 ANTONY CARR, university lecturer, Hundred Years' War

FRANCIS LAMBERT, university lecturer, Brazil since Independence - 1822

This third Semi-final comes from Southampton University. MARTIN CABOURN SMITH, chartered accountant, British Naval History of the First World War

NEIL CROCKFORD, risk management consultant, Isle of Wight

GEORGE JOHNSTON, schoolmaster, Life and Works of Liszt ARTHUR GERARD, retired civil servant, British Cathedrals

This Semi-final is devoted to the four best runners-up from the initial 12 heats, and it is the last chance for a woman to make it to the Final. But there are three of them lined up against a lone male. So the odds should be in their favour. The contestants and their special subjects are:

MARGARET ASKEW , journalist. The Life and Career of Stonewall Jackson

JACQUELINE PEARSON. university lecturer. The Life and Works of Christopher Marlowe

GENA DAVIES, unemployed, Gemology ALAN BLACKBURN, law student, History of Northern Ireland from 1921

Four worthy contestants line up for this the final hurdle to the championship title of Mastermind 1975. They are:

JOHN HART, schoolmaster, Athens in 5th Century BC

FRANCIS LAMBERT, lecturer, Cuban History, 19th century onwards

GEORGE JOHNSTON, schoolmaster, French Literature 1600-1900

BEST RUNNER-UP