Dominic Thiem is bringing a secret weapon to next week’s Nitto ATP Finals – massive confidence down the stretch.An Infosys ATP Insights analysis reveals that Thiem places second on the Infosys ATP Under Pressure Leaderboard for the past 52 weeks, trailing only World No. 1 Rafael Nadal. Underpinning Thiem's success in this list is an eye-popping win percentage of 87.5 per cent in deciding sets.View the Infosys ATP Under Pressure LeaderboardDuring the past 52 weeks, when the match has gone to a decider, Thiem has found another gear to power himself to the finish line first. He has won an astonishing 14 of 16 deciding sets during this time.Thiem’s recent form in deciding sets has been picture perfect. In his past four tournaments, he has taken two titles (China Open / Erste Bank Open) and has won all six matches he has played that have gone to a deciding third set. Those six matches:China Open SF: d. No. 9 K. Khachanov 2-6, 7-6(5), 7-5China Open Final: d. No. 7 S. Tsitsipas 3-6, 6-4, 6-1Erste Bank Open Round of 16: d. No. 40 F. Verdasco 3-6, 6-3, 6-2Erste Bank Open SF: d. No. 11 M. Berrettini 3-6, 7-5, 6-3Erste Bank Open Final: d. No. 15 Diego Schwartzman 3-6, 6-4, 6-3Rolex Paris Masters Round of 32: d. No. 32 M. Raonic 7-6(5), 5-7, 6-4What’s even more impressive is that Thiem dropped the opening set in five of those six encounters and came back to win the match. Thiem has won a career-high five titles in 2019, and has won a combined seven three-set matches in those events.Earlier this season, Thiem captured the biggest title of his career in winning the Indian Wells ATP Masters 1000. He had to overcome Raonic in three sets (7-6(3), 6-7(3), 6-4) to win the semi-final and backed it up with a thrilling three-set victory (3-6, 6-3, 7-5) against Roger Federer in the BNP Paribas Open final.Thiem’s form in this area has been up and down in the past few seasons. He was right at 87.5 per cent deciding sets won in 2016 (same as 2019 to date) and finished 11th last year in this specific category, winning 70 per cent.Dominic Thiem - Deciding Sets Won (since taking his first ATP title in 2015)2015 = 52.6% (No. 43)2016 = 87.5% (No. 5)2017 = 36.8% (No. 75)2018 = 70% (No. 11) 2019 (to date) = 87.5% (No. 2)Confidence comes to players in a variety of ways. Thiem’s recent purple patch of physical and mental fortitude in deciding sets is an “X Factor” he is bringing to this year’s Nitto ATP Finals.