At 2016’s first ‘match point’ round in Mexico Rosberg would have had to win the race and rely on the remote likelihood of eventual race winner Lewis Hamilton finishing tenth or lower to seal the deal.
Instead reigning world champion Hamilton, embarking on an uphill title defence after a patchy season coloured by intermittent mechanical troubles, cruised to pole position and an easy win on an off weekend for the title leader, who settled for second.
At the penultimate Brazilian Grand Prix, however, the mathematics of the situation is acute: with 25 points available for a race win a Rosberg-Hamilton one-two finish would grow the German’s 19-point lead into an unassailable 26 points with one round to spare.
With the championship within touching distance the fan-favourite Autódromo José Carlos Pace is the closest Rosberg has ever been to winning his elusive first crown.
Though the 2014 season was decided at the year’s final race in Abu Dhabi, Rosberg’s 17-point deficit to Hamilton made his title hopes unlikely at best before mid-race technical gremlins eliminated him from contention altogether.
In 2015 Rosberg’s title chances were academic, and Hamilton easily overpowered his teammate three rounds out from the finish.
The 2016 season has been the most evenly matched of the Mercedes teammates’ years leading the championship race, with momentum taking turns to swing wildly between each driver.
Rosberg opened the year with four wins in a row for an early lead before Hamilton seized the advantage with six wins in the next eight races.
Rosberg’s four wins from five after the mid-season break won him back his lead, but the last two rounds have proved straightforward affairs for Hamilton after the Briton came to terms with the prospect of defeat.
Working in Rosberg’s favour is his record in Brazil. Only three drivers in history have more than Rosberg’s two Brazilian grand prix wins, and both victories have come in the last two seasons.
Though Hamilton has sealed his own championship in Brazil after he finished fourth in 2008, his career has yielded only three Brazilian podiums from nine starts, including two second-place finishes behind his teammate in 2014 and 2015.
The form guide leans towards Rosberg, but old Interlagos brings with it the promise of unpredictable weather around the claustrophobic 4.3-kilometre circuit.
The circuit last decided a championship in 2012, when title leader Sebastian Vettel was forced to claw his way up from 22nd to sixth to secure his third crown from Fernando Alonso in a frenetic grand prix.
It was the only Brazilian Grand Prix Red Bull Racing failed to win during its four-year championship tenure, and its renewed pace in the 2016 season is sure to see it play a part in the fight for the podium.
But the championship permutations will take a back seat for the famously partisan fans, which will be out in force to see off the retiring Felipe Massa at his last Brazilian Grand Prix.
Massa, who was born in Sao Paulo, forever endeared himself to the enthusiastic crowd in 2008 with his dignified title defeat at the hands of Lewis Hamilton in F1’s most dramatic season finale.
Williams has been unable to deliver Massa a race-winning car in 2016, but his hard-fought third place in 2014 will be on the minds of his Brazilian supporters as they attempt to propel him to a fairytale final podium.
It is Brazil, after all, where stranger things usually happen.