ANSWERS TO CORRESPONDENTS: Have any innovations in sport been as game-changing as the Fosbury Flop in the high jump?

QUESTION: Have any innovations in sport been as game-changing as the Fosbury Flop in the high jump?

I would point to the introduction of the fibreglass pole for the pole vault in the 1950s. Prior to that, poles were rigid and made of wood or aluminium.

Elite vaulters began switching to fibreglass after Herb Jenks introduced his Browning Sky Pole in the early 1960s. Jenkss pole was more robust than earlier fibreglass poles, which were prone to breaking. 

Once it was discovered that the flexibility of the new poles meant the recoil could help boost the vaulter over the bar, it became obvious that a new technique was needed.

Fibreglass poles have since evolved into the sophisticated models used today.

Armand Duplantis of Sweden competes in the Mens Pole Vault during the World Athletics Diamond League

Dick Fosbury, of the United States, clears the bar in the high jump competition at the 1968 Mexico City Olympics 

Gold medal winner Dick Fosbury raises his arm on the victors podium of the Olympic stadium in 1968 

In 1960 the pole vault world record was 4.8 metres, today its 6.26 metres. In comparison, the high jump in 1960 was 2.2 metres, today its only 2.45 metres. So, you could argue that the invention of the fibreglass pole had much more impact than the Fosbury Flop, first used by Dick Fosbury in 1968.

Cecil Lowry, Stockport

QUESTION: When and why did a white flag become the sign for surrender?

The white flag was formalised in ­international law as a sign of surrender, truce or ­parley in conflict during the Hague ­Convention of 1899.

It was a practical choice because of its simplicity and visibility in battle. White stands out against chaotic backgrounds and lacks offensive symbolism, so it is understood across cultures and armies.

The white flag has been used throughout history. Roman historian Livy wrote that during the Second Punic War (218-201 BC), the Carthaginians signalled their desire for peace with bands of white wool and branches of olive.

It became widespread from the Middle Ages. In 1578, the English sailor George Best, searching for the Northwest ­Passage, described encountering the Inuit people, who signalled their peaceful intentions with a white flag made of bladders sowed together with the guts and sinewes of beasts.

Colin Hay, Cromer, Norfolk

QUESTION: Was Sean Connerys role of Zed in Zardoz the most bizarre piece of movie casting ever?

Further to the earlier answers, what about Keanu Reevess ­portrayal of Jonathan Harker in a 1992 adaptation of Bram Stokers Dracula? 

Denise Richards playing a nuclear physicist called Christmas Jones in the James Bond film The World Is Not Enough further stretched the imagination.

Annie Forbes, Brighton