Why tennis is one up on golf in Olympic medal battle?

Serena Williams with 2012 London Olympics gold medal

Golf's return to Olympics is overshadowed by which player is pulling out of the Rio 2016 Games. None of the top four in men's golf will be part of the Rio Games.The men will have only eight of the top 20 in the world, including Masters champion Danny Willett of England and British Open champion Henrik Stenson of Sweden.  
 

 
Rory MciLroy, Jordan Speith, Jason Day and Dustion Johnson have refused to go to Rio.
Tennis, however, will see top ten ranked players in men's as well as women's category battling out for the top honours in the Summer Games. Novak Djokovic, Andy Murray, Roger Federer and Rafael Nadal will fight it out for the men's singles while Serena Williams to face stiff challenge from the other top ranked women players..  
 

 
Tennis was first contested as an Olympic sport in the 1896 Olympic Games, held in Athens. In the inaugural Olympic Games, only two tournaments were played: men's singlesand men's doubles.

Women were allowed to start to compete in singles and mixed doubles tennis events at the Olympic Games in 1900. Between 1928 and 1988, tennis was not included in the official Olympic program. Demonstration tennis events were, however, held twice, first in 1968 and later 1984. It was reinstated as a medal sport in 1988.
 

 
Kathleen McKane Godfree is the all-time record holder for the most Olympic medals in tennis, with one gold, two silvers, and two bronzes. Six players have earned four medals including Serena Williams and Venus Williams who sit on top of the overall medal table with four gold medals. Eight Americans have earned two or more gold medals, while a further ten athletes from other countries have achieved the feat, including six from Great Britain and two from France.