Since the advent of the internet, sports gambling in Ireland and throughout the world has expanded dramatically. It is not that long ago that gambling on sports was generally confined to horse racing, football and the GAA sports in Ireland, but if you log on to any of the major bookmaker’s online gambling sites you will find a huge range of sports on which you can place a bet. One of these relatively new gambling sports is tennis, and gambling on tennis is a growing activity because there is now a major tournament with the top players competing almost every week of the year. This week for instance has seen the start of the 2012 Masters Series with the BNP Parabas Open being held in the desert at Indian Wells, and all the top players are competing for a first prize of $ 1 million for the singles champion. One of the features of tennis gambling in recent years has been the almost total domination of the top four players in all the major men’s singles tournaments, with most of the titles being shared between Novak Djokovic, Rafeal Nadal, Roger Federer and of course Andy Murray. If the seedings go to plan, these four will meet again in the semi-finals in Indian Wells next Saturday, with Djokovic having the chance to avenge his defeat to Murray in Dubai last week. Tennis gambling fans will know that although Murray has yet to win one of the Majors, he is perfectly capable of beating anyone in the three set format of the Masters Series. The other semi-final is likely to be Nadal versus Federer, and although Nadal has a significant advantage in their head to head matches Federer won the tournament in Dubai and is clearly in form. Most sports fans gambling on tennis would probably assume that these four will again reach the semi-finals, but who will come out on top. Check the odds and make your choice, unless of course you fancy one of the outsiders to break the hold these four appear to have.