As the London 2012 Olympics concluded, the overwhelming emotion for the vast army of BBC executives, consumed for years by a project on the grandest of scales, was relief at a job well done.

Just as trepidation slowly gave way to triumph for the organisers, so there was widespread acknowledgement that London 2012 had also shown the BBC at its best. Like the volunteers who gave the Games its unique flavour, the athletes who delivered the best haul of British medals for more than a century and Danny Boyle’s singular opening ceremony, the BBC’s coverage became part of the story of that golden summer.

Few could have predicted that, four short years later, the Rio Olympics would be the last Games at which the BBC would provide comprehensive coverage. Indeed, it is not long ago that the BBC was facing the unthinkable prospect of losing the Games altogether. Discovery sent shockwaves through the market last summer by seizing the exclusive pan-European rights to the Olympics for £920m, leaving the BBC’s position uncertain.

In the end, a compromise was brokered. From 2018 onwards, the BBC would share UK rights with the ambitious, Discovery-owned Eurosport.

It paid around £110m and gave up its exclusive rights to the 2018 and 2020 Games in order to be able to show live coverage of the biggest moments across two channels until at least 2024.

There was a sense during London 2012 that the BBC owned the whole thing… it was the only route to the Olympics

The general sense among BBC Sport executives, negotiating their way through a series of budget cuts and a bruising Charter renewal process, was, once again, relief. Barbara Slater, the BBC’s Director of Sport since 2009, says the deal was vital: “The coverage that the BBC will offer going forward will still be incredibly comprehensive – the baton for ‘never miss a moment’ hands on to Eurosport and we retain our special place as the curator of the best. There’s no restriction on what we can show.”

But, first, there is the small matter of Rio. This summer’s Games should be a carnival of colour and excitement, but Rio is facing greater challenges than perhaps any Games of modern times.

There is the threat of the Zika virus and the backdrop of political and economic turmoil, plus growing cynicism about doping and corruption.

Slater says that the key for the BBC will be to remember the lessons of London. “What London 2012 demonstrated was that lots of audiences want to experience the Games in different ways – the breadth and depth of the coverage [is what] people loved. That is definitely what we are trying to do with Rio.”

The first-ever South American Games is also the first to take place  in a “minus” time zone since the accursed Atlanta Olympics in 1996. This presents its own challenges.

Roger Mosey, Slater’s predecessor as Director of Sport, who oversaw the BBC’s London 2012 coverage, before leaving in 2013, says that the time zone will present particular difficulties. “In many ways, it’s easier when it’s the other way around, and you’re broadcasting the big live moments in the afternoon,” he says.

Some of the biggest moments, such as Usain Bolt’s attempt to win his third successive 100m title, won’t be broadcast live until the early hours.

But, says the defiantly glass-half-full Slater, that will allow a bigger live showcase for other sports in peak time in the UK. Some of those, such as gymnastics and cycling, are among the sports that have boomed in the UK since the British medal rush started in 2008.

Slater, herself a former gymnast, who competed at the 1976 Olympics, says that if the BBC had lost the Olympic rights it would have been more difficult to make the case for covering these sports in the years in between. “We have always tried to serve those sports well with coverage from world and European championships. That’s pretty difficult if you don’t have the Olympic Games,” she says.

She points to the huge uplift in interest in Britain’s gymnasts since the last Olympics, thanks to sustained success.

“We are incredibly proud to be the Olympic broadcaster. Those sports can be extremely successful – the figures from the Glasgow World Gymnastics Championships were phenomenal.”

Technology has also marched on. The sight of commuters catching up on highlights or “snack-sized” programmes on their smartphones has become commonplace.

Meanwhile, families often settle down in front of their main television with a tablet or phone on their lap, augmenting or complementing their viewing on a second screen.

Slater says that a key lesson of its coverage of the Fifa Women’s World Cup from Canada last year was that well-­produced catch-up content from the previous evening could be a real hit.

“The massive advance from London 2012 is in things such as speed – we have much better behind-the-scenes infrastructure facilitating everything we do,” she says. “You’ll be able to take the alerts you want. You will be able to choose and customise your experience. Different people will want really quick, really short-form content. All pulled together into a really good, bite-sized product.”

The time difference will also mean an important catch-up role for BBC Breakfast. Its iconic red sofa is physically moving down two flights of stairs to BBC Sport’s Salford home for the duration of the Games.

[Rio suffers] the threat of the Zika virus and the backdrop of political and economic turmoil, plus… cynicism about doping

The live action will be spread across two channels – BBC One and, in another reminder of the changes since 2012, BBC Four, rather than the now online-only BBC Three.

“The hours of BBC Four are being extended. The Olympics is just too good not to have two networks. With two channels, you can offer a proper choice,” says Slater. Up to 24 sports will have dedicated streams online, with up to eight on the red button.

“When you say 24/7, it’s not only across hours but across all media devices: 550 hours on BBC One and BBC Four, alongside Radio 5 Live,” she enthuses. “More than 3,000 hours of live coverage; 24 streams. It’s relatively cost-effective to stream content.”

Mosey, now Master of Selwyn College, Cambridge, accepts that Rio will represent something of the end of an era for the BBC’s Olympic coverage, but believes that the Eurosport deal was probably the best that it could have been done in the circumstances.

“It was very good for the BBC that it did the deal with Eurosport, and the deal it has emerged with is good,” he says. “But there was a sense during London 2012 that the BBC owned the whole thing and the only route to the Olympics was through the BBC.

“That sense of the nation coming together for one enormous event is not something that you can replicate again,” he argues. “In the end, most people will get most of what they want from the BBC.

“But that sense of enterprise and entrepreneurship that we were able to bring to London 2012 will get harder now that the rights landscape has shifted.” 

Much of the presenting talent will be familiar from London, with Gabby Logan and Clare Balding again taking central roles. The experienced line-up includes Hazel Irvine, Jason Mohammad, Dan Walker, Matt Baker, Helen Skelton, Eleanor Oldroyd and Mark Chapman. New pundits include former athletes Becky Adlington and Victoria Pendleton.

The BBC will take more than 400 staff to Rio. So far, it has avoided the usual newspaper sniping about the scale of the operation. Numbers are 40% down on London 2012.

One day, says Slater, it may be possible to direct coverage from London but, despite advances in technology, the time delay is still too great at present.

One notable absentee will be Gary Lineker, who will stay in the UK to concentrate on the start of the football season. He has a date with his underpants in the Match of the Day studio.

Olympic gold medallist Jonathan Edwards will also be missing from the TV coverage, having decamped to front Eurosport’s programmes. He will, however, be reporting for BBC 5 Live.

The balance between news and sport will also be more delicate than ever, given the plethora of issues swirling around these Games – not least, the doping cloud that will hang over them, whether or not Russian athletes are allowed to compete.

And Channel 4 will also be busy working out how to follow up the success of its bold gamble to screen the London Paralympics. Again, the challenge will be to cope with the time zone – and the fact that the focus will inevitably be less intense than four years ago.

For Slater, these Games – the last the BBC will broadcast on this scale but not, thankfully, the end of its long, emotive link with the world’s biggest sporting event – will be a celebration, too, of what the BBC can bring to sport.

They could also be a reminder, at the end of a bruising period financially, of just what sport can bring to the BBC. Slater says: “We’re trying to do the very best with the resources we have to bring to audiences as many of those moments that matter to the public.”