YOU can tell how well Roger Federer has played by the amount of post-match questions he gets asked about tennis.

After all, how many times can you ask the five-time champion about his forehand or his first serve percentage?

He held court on a wide range of subjects yesterday, from Michael Jackson to Nelson Mandela, as if his 6-3, 6-2, 6-7, 6-1 third-round win over Phillip Kohlschreiber was a formality, a mere accessory to the fact.

The five-time champion has dropped just 12 games on his progress to the last 16 and can now enjoy a long weekend, safe in the knowledge he’s still the one to beat.

However, this win was not as ruthlessly complete as his previous victory over Guillermo Garcia-Lopez, or as convincing as third seed Andy Murray’s victory over Ernests Gulbis the night before.

“I’m very pleased with how I am playing,” said Federer.

“I still thought this was my best match yet, even though I dropped a set.

“ I would have loved to have won it straight but I let my serve go a little bit in the third and he deserved a fourth set.

“But I didn’t panic and I’m happy with how I reacted.

“The only important thing is to come through the match and you feel good when you walk off court. I did both those things, so I’m happy.”

If the second seed – seeking an unprecedented 15th slam victory – makes history a week tomorrow, then the name of third-round opponent Kohlschreiber will be a footnote to the story.

However, the German world number 27 deserves more than that after putting up a valiant but ultimately futile challenge on his centre court debut.

He had never taken a set off Federer in three previous meetings and had twice lost to him c o n - v i n c - ingly on grass at the p r e - W i m b l e - don warm-up tournament at Halle.

But he forced the match to four sets after winning a third set tie-break and, on occasions, he even dictated play, something not many have done against the Swiss on a court he has often made his own.

“He looks so easy and smooth but you know that when you play him, most of the time you are going to lose,” said Kohlschreiber.

“He was just too good – he is unbelievable. I’m trying to think of something I could have done differently but I can’t.

“Sometimes there is just nothing you can do.”

This was Federer’s 47th win at Wimbledon, eclipsing a record previously held by Andre Agassi.

But that’s a fact that will interest only the most die-hard of tennis anoraks.

A keen student of tennis history, Federer likes breaking records, but the only one he really cares about is taking another Grand Slam, to confirm himself as the greatest player of all-time.

“I never knew that record existed,” he admitted.

“I mean, it’s not the sort of thing you dream about as a boy is it? It’s nice to get but I bet Andre didn’t even know he had it.”

Federer will now face Sweden’s Robin Soderling, who he beat so convincingly in the final of the recent French Open at Roland Garros, following his 7-6, 6-4, 6-4 win over Nicolas Almagro.

But he conceded Murray is the one he’ll have to beat.

“I didn’t watch his secondround match but he’s playing well,” added Federer.

“He came through convincingly and he’s certainly the favourite in the other section of the draw.

“However, my focus is on my side of the draw and I’m not thinking too far ahead.”

Soderling is a star on the rise and should not be dismissed.

Few gave him a chance of beating Rafael Nadal on clay but he did.

“Robin has got a taste for beating the top players and that makes him dangerous,”

added Federer “However, I’ve beaten him many times and that gives me an incredible amount of confidence.

“He’s proven his point that he is a good all-around player.

But I know that if I play my game I should be fine. However, you never know, that’s why I have to be very careful.”