The Davis Cup final is at last upon us in just a few days time, Belgium and Great Britain ready to face off for what is often termed 'the world cup of tennis'. Here's a look back at how the World Group has played out in 2015.

Defending champions out in round one

Switzerland, the 2014 champions, began their title defence with a very different team to the one that had won the country's first title a few months previously. The top Swiss player was the unknown Henri Laaksonen, ranked just inside the top 200, a far cry from the team that had boasted two top five players in 2014. The Swiss made a good fight of the tie, though, before eventually being defeated by David Goffin's decisive fifth-rubber victory over Adrien Bossel.

Such was the weakness of the Swiss team in round one that it would perhaps have been more of a surprise had they reached the quarterfinals- the Davis Cup is an odd competition in that the defending champions can have the odds so stacked against them in the following year.

The other major shock in the first round was Great Britain's second consecutive victory over the USA. On paper, the American team was by far the stronger, with two top 50 players and the formidable Bryan brothers to call on in doubles. The tie turned, however, on unfancied James Ward's heroics against John Isner in the second rubber.

Expected to be an easy win for Isner, the American took a two sets to love lead, and he looked to be on course for a routine win. Ward had other ideas, though, and completed a stunning comeback over a player far his superior in the rankings by winning the fifth set 15-13. After a tight doubles match which saw the Bryans taken to 9-7 in the final set by the British team of Dom Inglot and Jamie Murray, Andy Murray finished off the win with a straight sets win over Isner.

Other first-round results saw Kazakhstan overcoming Italy, France knocking out neighbours Germany, and a 5-0 whitwash of Croatia by Serbia

Raonic-less Canada swept aside by Belgium

The quarterfinals offered up another example of how the lack of a team's top player can utterly ruin their chances of progression, this time in the form of Canada, forced to field Frank Dancevic as their top singles player. Even the vast experience of Canada's 43 year old doubles specialist Daniel Nestor couldn't prevent his team from falling to a 5-0 defeat.

Elsewhere, Australia made surprisingly hard work of beating Kazakhstan 3-2, only a fifth rubber victory by (who else?) Lleyton Hewitt sending them into the last four after youngsters Thanasi Kokkinakis and Nick Kyrgios had disappointed on the first day.

Argentina put out a Serbian team featuring Victor Troicki as their top singles player - an important moment in the competition, as when world number one Novak Djokovic commits to the team, the Serbians become very tough to beat indeed. Had Serbia reached the semifinals, Djokovic surely would have been at least tempted to play, at which point they would have become favourites for the competition.

Great Britain staged their second upset of the tournament with a 3-1 victory over France, a French team featuring Jo-Wilfried Tsonga, Gilles Simon and Richard Gasquet unable to cope with a triple shift from Andy Murray, winning both singles matches and helping his brother to victory in the doubles. After a shaky start to the fourth rubber from the world number two, he raced to victory, 6-0 in the fourth set to send Great Britain into the semifinals.

Murrays again see Great Britain through semifinals

Having been responsible for all three of Great Britain's victories in the quarterfinals agains France, the Murray brothers pulled the same trick against Australia, Andy overcoming Kokkinakis and Bernard Tomic and teaming up with Jamie to win the crucial doubles rubber.

The lack of a doubles specialist withing the Australian team was always likely to hurt them, with Andy Murray looking almost certain to win two matches, and Great Britain's strength in depth with doubles players. That did indeed prove to be the case, although with a number of young Australian players gaining experience, their team could be formidable indeed in a few years time.

Argentina faced Belguim for the other place in the final, and they took a 2-1 lead after the first two days. Once Gofffin had leveled the tie with his expected win over Diego Schartzmann, it came down to a decisive rubber between Steve Darcis and Feliciano Delbonis to decide the tie - the world number 64 and 65 respectively. Delbonis fought hard to save two match points at 4-5 down in the fourth set, before eventually losing it in a tiebreak.

That sent Belguim into their first final in 111 years, where they will face Great Britain for the title from the 27th-29th November.

Poland reach World Group for first time

The World Group Playoffs saw few surprises, with the only change to the World Group teams for 2016 being the introduction of Poland at the expense of Brazil.

Poland have never been part of the World Group before, and made it with a 3-2 win over Slovakia with a team led by Jerzy Janowicz and Marcin Matkowski. The first opponents for the Polish in the competition's top tier will be Argentina when the 2016 tournament begins in March​.

In other ties, Kei Nishikori helped Japan to a 3-2 victory over Columbia to preserve their World Group status, Taro Daniel's fifth rubber win over the player ranked immediately above him, Alejandro Falla, sealing the win for the Japanese.

Nishikori was not the only big name in action for the Playoffs, either, as Roger Federer and Stan Wawrinka returned to the Swiss team to help them to a 4-1 victory over the Netherlands, keeping​ them in the top tier of the tournament.

Elsewhere, India, Uzbekistan and Russia each saw their World Group ambitions ended for another year at the hands of the Czech Republic, the USA and Italy.

One tie left to play

2015 has seen a fascinating World Group, with two worthy, if perhaps unexpected, finalists. Either team would be deserved winners in the final, although Murray's presence probably makes Great Britain the favourites. Whoever wins will not have long to dwell on their victory - only three months later they will be back in action needing a win to avoid a relegation playoff later in 2016.

Stay tuned to VAVEL over the next few weeks for all of our build up to the huge Davis Cup final as GB take on Belgium.  We'll be bringing you more reviews of all the action, more previews and more indepth discussion.  

Why not have a look at our review of Group 1? - https://www.vavel.com/en/tennis/563598-davis-cup-group-i-review-nadal-to-the-rescue-for-spain.html