Nadal - ended in bludgeoning, three-sets-to-one wins.And it isnt just Slam

The duel between Andy Murray and Novak Djokovic promises to be the dominant story of next week’s ATP World Tour Finals. On the line is not just a title, money and the prestige of victory, but also the right to start 2017 as the No 1-ranked player in the world. The stakes at this late stage of a year have seldom been as high.One man, however, is plotting a different narrative. Live Tennis: ATP World Tour Finals November 13, 2016, 12:00pm Live on Get Sky Sports Get a Sky Sports pass Stan Wawrinka has made a habit of ripping up scripts over the past three seasons and all of the signs suggest he is ready to do it again at the O2.His record at the event is not in itself outstanding and can be viewed in one of two ways: three successive semi-final appearances hinting at pedigree but a career record of six wins and six defeats suggesting vulnerability. Wawrinka has been a semi-finallist in each of the past three years The 31-year-old Swiss also arrives in London in poor form, after exits in the last 16 of the Shanghai Masters and the quarter-finals in Basel were followed by a meek defeat to world No 91 Jan-Lennard Struff in the last 32 of the Paris Masters last week.But Murray, Djokovic and the other tournament hopefuls should beware the wounded animal, because Wawrinka has proven in recent years to be a tennis alchemist capable of turning dreadful sequences of results into silverware at subsequent Grand Slams.He went to both the 2015 French Open and this years US Open on the back of a spree of abject performances and humbling defeats yet won both, and he wasnt exactly on fire in the build-up to his 2014 Australian Open triumph either.The problem for rivals is that, once he gets on a roll, he is near-impossible to stop. Not even pressure seems to affect him. ATP Finals: The groups Who will play who in the round robin at the O2 In fact, the biggest stages tend to bring out his best performances and all three of those Grand Slam final appearances - two against Djokovic and one against Rafael Nadal - ended in bludgeoning, three-sets-to-one wins.And it isnt just Slam finals where Wawrinka flourishes. His return of 15 wins from 25 career finals is not sparkling as such, but his 11 victories from his past 12 finals - stretching back to January 2014 - is unparalleled anywhere in the sport, better than both Djokovic and Serena Williams. Mark Petchey believes Andy Murrays group could not have been harder It would have been a perfect 12 in a row had it not been for a shock defeat to 19-year-old German Alexander Zverev in the final of the St Petersburg Open in September, an anomalous result that leaves his record in finals in 2016 at a still-impressive four wins and one defeat.New rankings-topper Murray will also be conscious of the fact that Wawrinka has won all three times he has faced the world No 1 in a final, so should the pair meet in next Sundays title decider, the in-form Scot may well be favourite in the bookmakers eyes but definitely not in his opponents.