LONDON (AP) _ From muddy rugby fields of northern England to plush professional boxing arenas in the south, Britain's image of fair play and turn-the-other-chee k stoicism in sports is taking a sock on the jaw from on-field violence.

The pattern will continue, experts say, until punishment is increased and competitors learn there is more to sport than money and winning.

In the past week, sports headlines in British newspapers and TV and radio broadcasts have focused on a boxer who attacked the referee in the ring, a mass brawl at a professional rugby match and a record number of soccer player dismissals.

It's all a far cry from the playing fields of Eton and Harrow, of Oxford and Cambridge, where the reputation of British sportsmen for playing hard but fair was nurtured.

''It all comes down to how players perceive the potential negative effects of stepping out of line,'' Stuart Biddle, a leading sports psychologist, said. ''If the rewards outweigh the punishments, then bad behavior will continue.''

Biddle, head of the psychology division at the British Association of Sports Scientists, said the lure of big money and a win-at-all-costs attitude are severely damaging sporting ethics.

''In amateur sport, the reward might be prestige. For the professionals, it's money,'' he said. ''It's not as bad here as in some countries. North American ice hockey, for instance, has a terrible violence record.

''But we still go far over the top in this country about winning and losing. It is very important that we should not lose sight of the original aims, which are to do the best we can, and enjoy it. If we over-emphasize results above skills and enjoyment, the problems will remain.''

British soccer long has been troubled by fan violence but this season the trouble has been mainly on the field.

Last weekend, three more players were sent off in the English league, bringing to a record 122 the number of expulsions in just 16 weeks of the 38- week season. For all of last season, dismissals totalled 215.

In Scotland, on-field violence at one game was deemed so serious that authorities brought charges against four players for breaching the peace, a rare intrusion into the game by the state.

These unsavory statistics make grim reading for soccer officials desperately trying to put the game back on its feet after the 1985 Heysel stadium and Bradford fire disasters, in which a total of 95 people died.

''After Heysel and Bradford, I was genuinely optimistic that everybody in the game was pulling together to create a better product,'' said Gordon Taylor, secretary of the Professional Footballers Association. ''But suddenly, it seems the message is not getting through. The same clubs, the same players, are repeated offenders.''

Taylor, like Biddle, agreed that the penalties may not be stiff enough.

''At the moment, a player is automatically banned for two games after he has been sent off,'' Taylor said. ''It may well be this penalty is not sufficient. Maybe the suspension will have to be increased to five matches.''

Taylor's assistant at the PFA, Brendan Batson, said it was vital for players, managers and referees to try to resolve the problem of bad behavior.

''At present, the interpretation of the laws of the game seem to be full of inconsistencies,'' Batson said. ''Players are finding it difficult to come to terms with how different referees officiate. Until there is an openness on everybody's part to come together, we will always have a problem.''

Batson disagreed with the growing call for referees, who are amateurs, to become fully paid professionals like the players. But, he said, they could still become more involved.

''I would like to see referees paying regular visits to their local professional club and watch the players in training,'' he said. ''What happens in training basically is what happens on the field, and they would get a better feel for the way players react.''

While soccer officials deal with a new twist to an old problem, authorities in boxing and rugby are faced with new cases of competitor violence.

On Dec. 2, light-heavyeight boxer Bobby Frankham attacked the referee after refusing to accept defeat, then tried to restart the contest at the Wembley Conference Center against the victorious Billy Simms.

Thousands of television viewers watched Frankham, who had already been down twice, push and punch referee Richie Davies when he halted the non-title contest in the first round. Frankham also hurled his mouthpiece at ringside officials.

The British Boxing Board of Control has scheduled a disciplinary hearing for Frankham Dec. 16. He could be banned from the ring for life.

Four days after Frankham's attack, attention switched to a professional rugby match, where all 26 players for York and Dewsbury were involved in a four-minute brawl midway through the second half.

York director Albert Bond, who said he had gone onto the field to break up the fighting, was sent off by the referee for allegedly throwing a punch. Five of the players followed, three of them from Dewsbury.

Professional rugby in Britain is a family sport, especially in the north of England, and is rarely hit by this type of misbehavior among either players or fans.

The apparent trend towards on-field anarchy has prompted angry editorials in some British newspapers.

''Honest people have been asked to swallow the unacceptable and the dishonest,'' wrote the Daily Mail. ''Those nominally in charge should be warned that the state of play, nationally and globally, is so appalling that cynicism is only the forerunner of public disengagement.''

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