Double the excitement, as dashing duos shine

World number one Djokovic and Federer have barely broken sweat to reach the semi-finals of the year-ending tournament - the former dropping nine games in three round-robin matches and his great Swiss rival offering up a mere 13.

Ten of the first 11 singles matches in the round-robin stage failed to go the distance, with all kinds of reasons being put forward for the one-sided nature of the match-ups, from the slow court surface to fatigue.

Yet the world's eight best doubles teams have had crowds on the edge of their seats with some fast and furious action.

That was the case again on Friday when American world number one pairing Bob and Mike Bryan, true stars of the discipline after claiming 16 grand slam titles together, reached the semi-finals, celebrating a high-energy 7-6 (3) 7-6 (2) victory over Alexander Peya and Bruno Soares with their trademark "chest bump".

"This is one of the best courts in the world and it's where we want to play," Bob told Reuters. "Going out there playing in front of a packed house gets the adrenaline flowing, gives us goose bumps every time."

Half of the doubles matches so far have gone to sudden death match tiebreaks (the first pair to 10 points) and Bob says they are happy they are giving the London public value for money.

"The singles matches have been finished in like 50 minutes...that's too quick for a hot ticket that's expensive. The doubles matches add to the show.

"We're leaving it all out there and giving fans some drama."

Identical twin Mike said men's doubles is experiencing a boom, especially with the best doubles players sharing the year-end tournament spotlight with the singles since 2003.

"I think it's as strong as its ever been, we have all the legends around, guys that have won numerous slams like Daniel Nestor, Leander Paes, you've got the cream of the crop and some of the best singles guys jumping in too.

"The levels have improved so much. If we played the same as we were in 2003 when we were first world number ones we wouldn't even make the top 20 now."

While proud of their numerous achievements, Bob said the ATP could still do more to maximise the potential of a game more familiar with club players around the world.

"We have been lucky enough to have good turnouts at our matches over the last 10, 12 years," Bob said.

"But the ATP could step it up. They do a great job at this event and hopefully that carries over to other smaller events.

"Every doubles player today is extremely professional, everyone has a coach, no one parties, everyone hits the gym. Maybe 15, 20 years ago it was journeymen enjoying the lifestyle, now we are all here to win and only the best survive."

Both are already looking forward to the 2016 Rio Olympics when they will be aiming to defend their title at an event that will definitely attract the top singles players too.

"In the Olympics, everyone plays for that gold medal and that's the toughest doubles draw in tennis," Mike said.

"Indian Wells is traditionally good too, 23 of the top 30 (singles players) played doubles there. Everyone wants to see Rafa Nadal and Roger Federer playing another match.

"The doubles guys hold their own and it would be interesting to see more Olympic style events."

The Bryans, bidding for a first year-end title since 2009, take on French duo Julien Benneteau and Edouard Roger-Vasselin in Saturday's semi-finals.

Benneteau, ranked 26 in singles, said doubles should not be under-estimated.

"It's amazing to play here in doubles," he said. "Only in Davis Cup can we play with this kind of atmosphere in doubles.

"I think the ATP could do more and I know they are working on it and players are pushing them to work on it."