Sport has been through a revolution and we have hardly noticed. Been too busy watching it, I suppose. But there is not a leading sport in the calendar that has not undergone shocking, dramatic and apparently irreversible changes.

I’m not talking about equipment or technology or social change or money, though all these things are significant enough. I’m talking about changes to sport itself. The rules, the format, the actual shape of all leading sports has changed; in some cases radically, in some cases almost beyond recognition.

Cricket
It’s the World Twenty20 that prompts such thoughts, of course. To everybody’s surprise, this has been a fabulous tournament, full of flair, discipline, outrageous innovation and traditional cricketing skills. No one with cricket in his soul could fail to revel in it.

Cricket has been like an amoeba, constantly splitting in half to create new life forms. The process began in England in 1962 with a 65-over match, the Gillette Cup began in England the year after. The first World Cup was held in 1975. Since then, the standard format for one-day internationals has shrunk to 50 overs.

But this version stagnated and became formulaic. Cricket was refreshed with another example of simple fission in 2003. The Twenty20 format was invented, again in England, and in the past fortnight it has produced great sport. Can Test-match cricket survive? Those who love cricket will mostly agree that a mix of Tests and Twenty20 would be best.

Verdict: Test-match cricket needed limited-overs cricket to bring the game back to life. The 50-over format is dire. The present World Twenty20 is wonderful.

Football
In 1968, Italy beat USSR in the European Championship semi-final on the toss of a coin. This was plainly unsatisfactory, so in 1970, Uefa adopted the penalty shoot-out and Fifa did the same thing in 1976. In that year, the European Championship was won on penalties — by Czechoslovakia against West Germany. In 1994, the dullest World Cup final in history was won by Brazil on penalties against Italy after the match finished 0-0.

England went out of leading tournaments on penalties in 1990, 1996, 1998, 2004 and 2006, so there are parochial reasons for disliking the format. But there are other objections: the penalty competition is not football. It is just a way of ending a match with maximum speed and drama. Drama, not sporting excellence.

Verdict: a bad thing. The existence of the penalty competition encourages players to play for the draw, for losing on penalties is not quite the same as defeat. No one is blamed. The penalty competition encourages negative football and the very reason it was needed was because football had become so defensive. The penalty competition is an incitement to mediocrity — but no one in football administration cares. They just look at the viewing figures.

Tennis
A match at Wimbledon in 1969 between Pancho Gonzalez and Charlie Pasarell finished 22-24, 1-6, 16-14, 6-3, 11-9 to Gonzalez. Enough was then felt to be enough. The year after, the tie-break came in at the US Open; Wimbledon adopted it the next year. Now the tie-break is standard in all sets save the final ones at grand-slam tournaments, the US Open excepted.

Verdict: unqualified success. This format has everything that football’s penalty competition lacks. In the tie-break, the drama comes from sport, rather than gratuitous cruelty. The tie-break is essentially tennis: keep your own serve and attack your opponent’s.

The tie-break played by Roger Federer against Robin Söderling in the final of the French Open the other week was a classic example: Federer served four aces and destroyed his opponent’s serve. And, of course, there is the greatest tie-break — and one of the greatest bits of tennis — in history, between John McEnroe and Björn Borg in the Wimbledon final of 1980. McEnroe beat Borg 18-16 in the fourth-set tie-break only to lose the match.