A few years ago he would have been out there like a shot, but today his ill health prevents it. He would have remonstrated with them, tried to persuade them that they shouldn't be playing so close to the flats. Then he would have organised them into soccer teams. And he would have joined in the game given half the chance.
"I would love to go out and say to them 'hang on a minute. You're being terribly destructive. Who do you think is going to replace these goalposts? And I won't take no for an answer'."
Dick Allcock OBE spent most of his career refusing to take no for an answer. He began working with young people 60 years ago and became a pioneer in youth development work. In 1955 he founded Endeavour Training, which still promotes development and leadership skills.
A stroke in the early 1980s forced him into retirement and he now lives in Kenilworth, Warwickshire, with his wife Joan. Photographs from the 1950s and 1960s show him constructing a sled in Greenland and mountain climbing in Poland.
Ingrid Cranfield, a director of Endeavour Training, says his legacy should not be underestimated. "I think Dick saw exactly what was needed in providing for young people, especially at that time. There are those who argue that it's a bit outdated now, although that's a matter of opinion.
"But the central idea he had was that everybody was good at something. You get Tony Blair now talking about a stakeholder society. But Dick had the original idea of a stakeholder society in which everybody felt able to contribute something of themselves."
In his teens he ran a youth club on his parents' farm in Norfolk, for evacuees from Bethnal Green. After a decade of voluntary work and a stint as a housemaster for Dr Barnardo's, he became a professional youth worker in 1949 and began experimenting with adventure training.
In his book Development Training: A Personal View, he recalls the effects of a weekend of activities. "The transformation in what had previously been a passive, critical, cynical group of bystanders was amazing."
His first 10-day residential course in 1955, which included sailing, initiative exercises, birdwatching, and a 48-hour expedition along the Norfolk coast, became the blueprint for Endeavour Training.
Forty-four years on, Dick Allcock believes we have let young people down. "They don't give a great deal of respect. I know very well that my generation has failed them because we haven't been worthy of respect."
His down-to-earth approach has often brought him into conflict with authority, the Church, even icons of youth. He recalls a stormy meeting with the Beatles and the Maharishi Mahesh Yogi in the late 1960s .
"I went to this big house in Kensington. The room was full of reporters. John Lennon was stoned out of his mind. He was stuffing flowers in his mouth. Paul McCartney turned on me. He said who do you think you are to represent young people? I told him I had two mandates - one, my job and two, I was a parent. I said I'm one of the people who has to pick the kids out of the gutter who imitate you. We had a ding dong of a row for half an hour. I loved it."
Mr Allcock sees the learning process as an equilateral triangle. One corner is an academic grounding in numeracy, literacy and general knowledge. The second is developing skills in the commercial, scientific or technological fields. The third is about social skills - this is where he sees the responsibility of the youth service. And he says discipline in behaviour is essential ."Discipline is an internal thing. It's about making things work for you.
"Ninety per cent of the time it's about putting yourself on the spot. It's you being able to stand self-examination and be accountable. You're dealing with that fragile internal bit of the person, through which they are going to establish their pattern of life. It's a much more delicate and tender thing to handle than someone on the end of a rope on a rockface."