History is littered with instances of legends coming out of retirement for another shot at glory and not all are successful.
To come back or not
Athletes, like time, fall into three categories: past, present and future. It is a distinction which sees today's fathers wax lyrical about the idols of yesteryears to children obsessed with present day heroes. It is the nature of sport - legends emerge and retire, continually driving the "greatest" debates.
Once in a while though, a retired champion upsets the balance by coming back. Michael Schumacher's return to Ferrari - to replace the injured Brazilian Felipe Massa - is such an occasion: a past star back in the present. A seven-time world champion, Schumacher - the sport's undoubted best - bowed out of Formula One three years ago. Now, with Massa out for the season, Ferrari's prodigal son is back.
"For team loyalty reasons, I can't ignore this unfortunate situation," said Schumacher. "The F1 chapter has long been closed for me... [but] as the competitor I am, I look forward to facing this challenge," added the winner of 91 Grands Prix. Schumacher's comeback pits him against the likes of McLaren's Lewis Hamilton in an F1 grid packed with emerging youngsters - the future. The German is gambling with his legacy. Sporting history is filled with comeback stories.
Indeed, Niki Lauda's F1 journey will inspire Schumacher. Ferrari's double world champion in the mid-70's, Lauda quit in 1979, returned with McLaren in 1982 and landed a third world crown two years later. "I was 33 when I came out of retirement; Michael is 40 - but he will be brilliant. Watch him get in and go," said the Austrian. Boxing's annals overflow with returning heroes and dramatic post-retirement ring re-entrances - both good and bad.
Muhammad Ali retired after regaining his world title in 1978. A 1981 return, aged 39, saw him being badly beaten by world champion Larry Holmes. Alternatively, after 12 years out the ring, George Foreman - Ali's great rival - stunned boxing 15 years ago when, aged 45, he became its oldest-ever world champion by beating Michael Moorer in 1994. Boxing, and sport in general, loves comebacks; Lance Armstrong's is well documented.
The American cyclist survived testicular cancer before pedalling to seven successive Tour de France triumphs. The 37-year-old Texan's second Tour resurrection ended in a third place finish, but in typical never-say-die attitude of a champion, he's vowed to return next year - he can't help it. To basketball, and specifically Michael Jordan's 1993 exit from the Chicago Bulls. Jordan wanted to play baseball, but he returned to the Windy City in 1995 and led the Bulls to three NBA titles and became the most famous basketball player in history.
Jordan, however, was still in his prime when he originally retired and triumphantly returned. He wasn't during a failed Washington Wizards vanity stint from 2001-03. Tennis legend Bjorn Borg is another who timed his return badly. The Swede, having already won 11 grand slam titles, quit at 26. Returning at the age of 31, wielding an old wooden racket - itself a metaphor of his forgotten era. Borg did not win a match in 10 miserable tournaments.
For every Jordan or Foreman, there is an Ali or Borg, while Armstrong's and Lauda's careers are defined by comebacks. How will Schumacher's legacy be affected? Abu Dhabi will see for itself, in his "last" race - here at the Yas Marina Circuit - on November 1. email@example.com