The helmet that Phil Hugheswore on Tuesday was not protecting the base of his skull. Cricket helmets that are available in the market do not cover that soft spot.
Hughes' sickening injury from the Sean Abbott bouncer was a stark reminder of the inherent dangers faced by batsmen confronting bowlers propelling a five-and-a-half ounce ball at speeds of up to 90 miles per hour.
In a few cases such as Shoaib Akhtar, Jeff Thomson, Brett Lee and Shaun Tait, even 100 miles per hour.
Hughes died on Thursday, reviving an old debate on how batsmen should protect themselves from a blow on the head.
When former Australia cricketer Bryce McGain wore a new, safety-conscious helmet for a series of televised one-day matches a few years ago, he and quickly found himself the butt of commentator and player jibes.
"They explained the technology and I liked the idea that it was safer," McGain said of the futuristic-looking helmet he wore in 2009.
"The commentators had a go, saying 'He looks like Darth Vader', 'He looks like Robocop'."
"It didn't bother me too much, but only a couple of other players wore it and if you don't have the players at the top, the ones on TV, wearing them, they won't sell."
They didn't. Sports manufacturer Albion Sports Pty Ltd pulled the helmet, which was designed to provide more coverage and deflection capability, after poor sales.
Manufacturers say Hughes's accident was unusual and no cricket helmet available on the market now would likely have prevented it.
But they also say advances in cricket helmet technology are being stymied by a lack of enforcement of international safety standards and the reluctance of elite-level players who prefer the game's traditional aesthetics to adopt new styles.
Investment in new designs has gone instead to other sports such as cycling and baseball, which have been more open to radically different helmet designs than the "gentleman's game".
Patsy Hendren, the Middlesex and England batsman, briefly wore a reinforced, multiple-peaked cap made for him by his wife in 1933 following England's infamous 'Bodyline' tour of Australia in 1932/33 that led to a spate of short-pitched bowling.
Hendren quickly abandoned his innovation and for more than 40 years batsmen made do with caps, sunhats or, as was usually the case, nothing at all on their heads.
The Laws of Cricket were adjusted to rule that repeatedly bowling short-pitched deliveries was "unfair", although it was down to the umpires to make an assessment of the "relative skill" of the batsmen, largely so that those that were good at hooking the bouncer were not denied the opportunity.
However, it was rare to see bowlers warned, much less withdrawn from the attack, for bowling an excessive number of bouncers.
The mid-1970s saw England's Mike Brearley experiment with a protective skull-cap worn under the cap, with something similar worn later by India's Sunil Gavaskar.
But the most notable change in headgear came during Kerry Packer's 'rebel' World Series Cricket in the late 1970s which attracted an exceptional crop of fast bowlers, including the West Indies' Andy Roberts, Wayne Daniel, Michael Holding and Joel Garner.
With umpires seemingly reluctant to do anything about bouncer frequency, batsmen decided to treat their heads the same way they had long treated their legs and hands — by covering them up.
Dennis Amiss, pioneer who brought in ‘motorcycle’ helmet
England's Dennis Amiss, who had struggled against Australia's celebrated fast-bowling duo of Dennis Lillee and Jeff Thomson during the 1974/75 Ashes, was a pioneer of the batting helmet.
"I went to a motorcycle helmet manufacturer, and he came up with something lighter than the fibreglass motorcycle helmets around in those days and had a visor that could withstand a shotgun blast at 10 yards," Amiss told the Daily Telegraph.
"The problem was that it covered your ears, making it difficult to hear what your batting partner was saying, and we had a spate of run-outs."
Instead, the forerunner of the 'cap'-design helmet worn by Hughes became commonplace, with plastic visors giving way to grilles, although, for a long time, many batsmen used helmets without any facial protection.
Former England captain Michael Atherton, an opening batsman, writing in Wednesday's edition of The Times, said: "Maybe helmets had made us a little complacent, then. Certainly, they have changed the game beyond all recognition".
Atherton added that whereas in the pre-helmet era batsmen generally hooked cautiously and infrequently off the back foot, helmet-wearing players such as Australia's Matthew Hayden were emboldened to hook off the front foot, a potentially riskier option.
Yet Vivian Richards, one of cricket's greatest batsman, bucked the trend by hooking some of the fastest bowlers the game has known during the 1970s and 1980s with nothing more than a West Indies cap on his head.
"That you should cover yourself in a suit of armour, to make yourself brave, or to enable you to hook — when you never hooked in your life — just because you've got a helmet on. That's rubbish," Richards told the Guardian in 2009.
"Even though they say cricket is a gentleman's game, it's a man's game."
Yet no helmet can offer complete protection without at the same time making life uncomfortable for batsmen.
One way to improve batsmen's safety would be an outright ban on bouncers, yet no major figure within cricket believes ridding the game of its "terrible beauty", to use Atherton's phrase, is an option.
"Without fast bowling, without the physical threat, cricket is a lesser game," wrote Atherton. "But with that, comes inevitable risk."
Tradition trumps innovation in helmets
"The ability of manufacturers to innovate is reliant on players embracing new technology and they are very, very traditional in cricket," Brendan Denning, chief executive of Melbourne-based Albion, said in a telephone interview.
"At the moment, we make incremental changes while trying not to upset the traditionalists," Denning said. "Other sports, like horse racing, more readily accept that injury is an issue."
The International Cricket Council (ICC) and the British Standards Institution (BCI) agreed new helmet safety guidelines a year ago, the first revision of the code in 15 years. The changes focused on risks including a ball slipping between the faceguard and the peak and a ball hitting the faceguard.
Cricket Australia supports the new guidelines but neither the ICC nor any country regulators have moved to actively enforce the new rules, meaning players can continue to wear older helmets — if any at all.
"The issue now is having the professional and amateur players invest in the new products," said Tom Milsom, founder and director of another major manufacturer, Ayrtek Ltd. "What it all comes down to really is enforcement."
Albion's Denning said enforced standards "would justify us spending more on new technology".
The ICC, Cricket Australia and the Australian Cricketers' Association (ACA), which represents players, declined to comment on helmet technology. The ACA said safety was a major concern and it would review the Hughes incident.
British sports firm Masuri Group Ltd, which made the 'Original Test' helmet worn by Hughes, said its new 'Vision Series' model released about a year ago offers more protection. Masuri, the third major manufacturer of cricket helmets, declined to comment further.
Helmets have made some progress. Many now have faceguards manufactured from titanium and shells from carbon fibre, lighter materials than the traditional steel and specialist plastics.
Albion's Denning said there were still several more possibilities for improvement, dismissing arguments about potentially limiting mobility or visibility.
"You could say that for baseball and we've had queries from the US about making helmets for them," he said. "They're surpassing cricket."