A little guidebook* to the sport of rugby union reached me this week, containing some examples of what can happen when one of these variables goes awry.
In 1975, for instance, Ireland organised a centenary tour to New Zealand which included a warm-up game in Fiji. When they arrived in Fiji, the Irish tourists discovered the Fijian team was also on tour - in New Zealand. Right time, wrong place.
Then there was the winger who played for Villeneuve in a 1974 French club game against Villiers les Nancy. With his side 65-3 down, he intercepted a pass and sprinted for the try-line - but ran into a snowman. It had been built by the opposing full-back during his many spare moments. Right place, wrong time.
Another Frenchman, Jean Salut, tripped on the steps up to the pitch as he ran out for his international debut in 1969, breaking his ankle. He never played for France again. Simple bad luck that. But to return to the theme.
Right place, right time. There have been moments in my life when I have experienced that strange, calm certainty.
Fornebu airport in Oslo, three months ago. The previous evening, Haile Gebrselassie of Ethiopia had kept his word and regained the world 5,000 metres record. As I made my way to the gate for an early flight back to Heathrow, I reviewed the possible lines I might use for a follow-up story.
It was not an encouraging exercise. The deadlines had been such that I and most of my colleagues had not been able to attend the post-race press conference. Someone, I suddenly recalled, had a tape of it. Who was that person? Ah yes. That person was the person who was flying straight on to Stockholm. Wrong place, wrong time.
What I needed, it had to be said, in an ideal world, with the wind behind me, what I really needed was to speak with Haile Gebrselassie.
Turning 180 degrees, I saw a thin figure in a tracksuit standing on his own, his teeth impossibly white. "Haile," I said. "Congratulations on last night. Great run."
"Thank you," he said, very quietly, the half-smile widening into dazzling fullness. I asked him about his plans for the rest of the season...
It seemed mystical. It was, in retrospect, almost logical - the world record breaker was catching an early morning flight back to his Dutch training base, and I had simply got lucky.
But my Twickenham experience. That was mystical.
Accepting the offer of tickets for the 1981 Twickenham Sevens seemed like a fine idea at the time. My girlfriend's landlord played for Richmond, who were defending the title, and when he suggested we made up a party with his wife and her parents, we thought: why not?
Why not only became clear after we had committed ourselves both to the outing and the kind offer of a lift from the parents-in-law. When the tickets arrived a couple of weeks later I registered what I took to be a ghastly clerical error.
The date for rugby's end-of-season event - May 9 - appeared to clash with that paramount occasion in the British sporting calendar: the 1981 FA Cup final.
A brief enquiry of the resident defending champion confirmed the worst. The times were out of joint. Oh, wretched spite.
I tried. I tried until 3.00pm, that wasn't too hard. I tried after 3.00pm, watching London Irish against Saracens - or was it Wasps? - weaving their way over the Wembley, sorry, Twickenham turf.
A request from the father - "any chance of a beer?" - detached me from the dutiful gathering. I like to think good manners would otherwise have kept me there. They wouldn't, but I like to think they would.
Drifting behind the stand and past the bar, I was drawn instinctively to the Twickenham car park.
What I needed, it had to be said, in an ideal world, with the wind behind me, what I really needed was a television set.
Turning 90 degrees, I noticed a white marquee. Inside were many rows of plastic seats, all empty, all facing a little table on which stood a television set showing the 1981 FA Cup final.
One's first instinct in such transcendent moments is to expect life to throw out its grappling hooks. "Excuse me sir, can I help you?" That is what I expected to hear. "Are you with the main party?" That is what I expected to hear.
But all I heard was the rising excitement in Barry Davies's (or was it John Motson's?) voice as Tommy Hutchison gave Manchester City a 1-0 lead over Tottenham.
I thought: I'll just stay until half-time. At half-time I thought: I'll just stay until full time. At full-time I thought: I'll just stay until extra-time.
Towards the end of the match, some rugby people craned their heads round the doorway and jeered - genteely. "What kind of a game do you call that?" I felt able to smile indulgently.
Soon afterwards, a young lady in a white apron came in and offered me a bottle of cold beer. It came at the right time. And I knew the right place for it.
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