Call it sneaky, call it 'Sabre,' call it the new weapon that could just fire Roger Federer to his sixth US Open and 18th Grand Slam title.
The world number two has developed a new attacking ploy which is bamboozling opponents and providing the 34-year-old Swiss with yet another dimension to his already impressive game.
It involves chipping and charging on a second serve, starting from a position inside the baseline and ending with a quick sprint to the service box.
"We sort of came up with the name, you know, 'Sneak Attack By Roger,' 'Sabre.' Call it 'Fed Attack,' call it whatever you want, but I thought it was kind of funny," said Federer.
Although he had mixed success with it on Saturday, the world number two still had plenty of other tricks up his sleeve to make the last 16 with a 6-3, 6-4, 6-4 victory over Philipp Kohlschreiber.
It was his 10th victory in 10 meetings against the German player as he reached the second week in New York for the 15th successive year.
Federer arrived in New York having rebounded from his Wimbledon final defeat to Novak Djokovic with a seventh Cincinnati Masters title.
It was at the Midwest venue where Federer developed his new tactic, almost by accident when he was practicing with French player Benoit Paire.
Both men were just looking for a gentle workout with Federer still dazed by jet-lag and Paire laid low with an ear infection.
"I was very tired and he was tired, and at the end we said, 'Well, let's still play some games just because it feels like it's the right thing to do,'" explained Federer.
