Question: The 2013 World's Best Racehorse Rankings were sponsored by which luxury watch company?

Context articles: World's Best Racehorse Rankings
Longines
New Approach
Gun Runner (horse)
2013 World's Best Racehorse Rankings
2014 World's Best Racehorse Rankings
2015 World's Best Racehorse Rankings
Winx (horse)
2016 World's Best Racehorse Rankings
Christopher Ward (watchmaker)

The Longines World's Best Racehorse Rankings (LWBRR), known as World Thoroughbred Racehorse Rankings (WTRR) before 2012, are horseracing's equivalent to World Rankings by other major sporting organizations such as ATP Tennis Rankings, World Golf Rankings, FIFA World Rankings for soccer and IRB Rugby World Rankings.
 The Longines Rankings are based on the ratings earned by horses running worldwide from North and South America, Europe, Middle East, South Africa, Asia through to Australia and New Zealand.
Longines (] , ) is a luxury watch company based in Saint-Imier, Switzerland.
 Founded by Auguste Agassiz in 1832, it is currently owned by the Swatch Group.
 Its winged hourglass logo is the oldest registered trademark for a watchmaker.
New Approach (foaled 18 February 2005) is a retired Irish Thoroughbred racehorse and active stallion.
 In a racing career which lasted from July 2007 to October 2008 he ran eleven times and won eight races.
 He was undefeated in five races as a two-year-old in 2007 including the National Stakes and the Dewhurst Stakes.
 As a three-year-old he won the 2008 Epsom Derby, the Irish Champion Stakes and the Champion Stakes and was rated the best racehorse in the world (jointly with Curlin) in the 2008 World Thoroughbred Racehorse Rankings.
 In his first season at stud, New Approach sired the classic winners Dawn Approach and Talent.
Gun Runner (foaled March 8, 2013) is an American Thoroughbred racehorse who has won multiple graded stakes races and is one of the top ranked racehorses of 2017.
 As a three-year-old, he became an early favorite for the 2016 Kentucky Derby after winning both the Risen Star Stakes and Louisiana Derby.
 Following a third place finish in the Derby, he won the Matt Winn Stakes and Clark Handicap, and was second in the Breeders' Cup Dirt Mile and Pennsylvania Derby.
 As a four-year-old in 2017, he has won the Razorback Handicap, Stephen Foster Handicap, Whitney Stakes and Woodward Stakes, and finished second in the Dubai World Cup.
 His performance in the Whitney earned him a rating of 127 in the August 2017 update of the World's Best Racehorse Rankings, placing him third place worldwide.
The 2013 World's Best Racehorse Rankings, sponsored by Longines was the 2013 edition of the World's Best Racehorse Rankings.
 It was an assessment of Thoroughbred racehorses issued by the International Federation of Horseracing Authorities (IFHA) in January 2012.
 It included horses aged three or older which competed in flat races during 2013.
 It was open to all horses irrespective of where they raced or were trained...
The 2014 World's Best Racehorse Rankings, sponsored by Longines was the 2014 edition of the World's Best Racehorse Rankings.
 It was an assessment of Thoroughbred racehorses issued by the International Federation of Horseracing Authorities (IFHA) in January 2015.
 It included horses aged three or older which competed in flat races during 2014.
 It was open to all horses irrespective of where they raced or were trained.
The 2015 World's Best Racehorse Rankings, sponsored by Longines was the 2015 edition of the World's Best Racehorse Rankings.
 It was an assessment of Thoroughbred racehorses issued by the International Federation of Horseracing Authorities (IFHA) in January 2016.
 It included horses aged three or older which competed in flat races during 2015.
 It was open to all horses irrespective of where they raced or were trained.
Winx (foaled 14 September 2011) is a Champion Australian Thoroughbred racehorse.
 Starting in May 2015, she has won twenty consecutive stakes races at distances ranging from 1300m (roughly 6 ⁄ furlongs) to 2200m (roughly 11 furlongs).
 In the World's Best Racehorse Rankings, she was the second-ranked filly or mare in 2015, improving in 2016 to become both the world's top-ranked filly or mare and the world's top-ranked turf horse.
 She retains this ranking through July 2017.
 In 2017, Winx was inducted to the Australian Racing Hall of Fame, only the third horse to earn this honour while still in training.
The 2016 World's Best Racehorse Rankings, sponsored by Longines was the 2016 edition of the World's Best Racehorse Rankings.
 It was an assessment of Thoroughbred racehorses issued by the International Federation of Horseracing Authorities (IFHA) on 24 January 2017.
 It included horses aged three or older which competed in flat races during 2016.
 It was open to all horses irrespective of where they raced or were trained.
Christopher Ward (London), founded by Chris Ward, Mike France and Peter Ellis in 2004, is a British luxury watch company.
 It was the first on-line only luxury watch retailer selling timepieces direct to the consumer.