In some ways, the legendary career of Roger Federer has already entered a new phase. Calendar years with three Grand Slam titles aren’t likely to be repeated. Very genuinely, Federer is about to write a new chapter in his tennis life. The real question surrounding this 27-year-old superstar is as follows: How will this new entry in the Great Book of Federer be authored?

There are so many issues to think about when considering such a query. Are the next few years going to witness a complete absence of major titles, or will they bring about a steady but smaller stream of slam championships? Will Federer come close to steamrolling through tournaments other than Wimbledon? Will he lose some of his desire at the French Open? How consistent will Federer be?

These and other questions merit some examination in the wake of Sunday’s close-shave win over Tomas Berdych in five tense, confusing, and very uneven sets. Federer’s brush with early elimination has the tennis world abuzz heading into the Australian Open 2009 quarterfinals. Every fan wants to know: Which Roger will show up, not only in the round of 8 against Juan Martin Del Potro, but in future slams over the next two or three seasons?

Let’s then take a look back at Federer- Berdych. The questions that arose from Sunday’s fourth-round encounter will follow the ATP Tour in 2009 and beyond.

Question No. 1: Did Federer struggle against Berdych because of a pancake-flat performance, or due to the Czech’s punishing groundstrokes?

The verdict here is that Berdych’s combination of power and accuracy got into Fed’s head a little bit. Perhaps that shouldn’t have happened, given the mental toughness of this decade’s most successful player, but it did. Federer acknowledged in his post-match press conference that Berdych possesses top 3 talent in terms of serving and ballstriking ability. The candid assessment suggested that Federer was caught off guard by the early onslaught that floored him.

The tricky part of this issue is that Federer obviously knew about Berdych’s potential coming into the match. It’s well known in the tennis community that Berdych’s upset of Federer in the 2004 Summer Olympics made the Swiss aware of the need to respect every opponent.

Naturally, Federer intellectually knew what he was getting into on Sunday. After all, Federer defeated Berdych in the fourth round of the 2008 Australian Open. The idea that Fed was overconfident against a dangerous foe is extemely hard to believe.

Here’s the difficult question, then: Why did Federer exhibit such subdued body language in Sunday’s battle with the “Bird Man”? Why did Federer lack the low-key yet unmistakable swagger of a champion comfortable in his own skin?

The more one thinks about this topic, the more it seems that, against an in-form Berdych, Federer was guilty of nothing more than being human… human enough to doubt himself ever so slightly, and feed a massive dose of confidence to an historically erratic player. When Berdych stormed to a quick 3-0 lead, Federer might not have wondered how he would get back into the set. The Swiss might have been thinking, “Uh oh, what happens if this hugely talented guy simply refuses to miss shots, especially on big points?” For two and a half sets, that’s exactly what happened.

Berdych made very few errors, particularly in a second-set tiebreak that witnessed a master class from the 20th-seeded Czech. Tennis experts around the world have said that when Berdych is on, he can beat anyone. The problem is that Berdych has never attained complete focus in high-stakes Grand Slam matches.

So while Federer definitely had a bad day at the office, missing the easiest of open-court forehands, it nevertheless remains that Berdych’s consistently big and accurate hitting gave Roger Federer reason to doubt himself. The pressure he faces from other players, even the ones he’s already faced several times, will make Federe’s mind wander in his advanced tennis age. This is the price one pays on the downside of a career, when one’s most productive years are part of history, and not the present. This is the best way to explain why Sunday’s match was so noticeably disjointed.

Question No. 2: Was Federer’s narrow win over Berdych an indication that a five-set win in the fourth round of the 2008 U.S. Open was the sign of things to come?

The short answer is yes. Fed’s rollercoaster ride against Berdych in Australia bore a lot of similarities to the five-set win over Igor Andreev last September in New York. Federer lost his first service game in both matches, dropped a tiebreaker in both matches, saw his serve come and go in both matches, and ramped up the emotion in the fifth set of both matches. It certainly appears that the days of dominant runs through non-Wimbledon tournaments are over for Fed. Future slams are going to be won with at least one high-drama match in the round of 16, the quarters, or the semis of a slam (not counting the final). This is another part of being human, and going through (in tennis terms) the aging process.

Question No. 3: Does Fed’s shaky performance against Berdych mean that he’s in trouble on Tuesday against Del Potro?

In a word, no. This seems to contradict what’s been said up to now, but it paradoxically makes sense. Much as Federer played really well in the matches before and after his difficult U.S. Open match against Andreev, the Swiss dominated Marat Safin in the match before his bumpy ride against Berdych. The downside for Federer is that he’ll have to ride out bad days in future slam events. The good news is that if Fed can escape his sluggish and sloppy outings, he should get back on the beam in his next match. This analysis would need to be revised only if Federer starts losing regularly in the middle rounds of slam tournaments. That’s a development we’re not likely to see anytime soon.

What will become of Roger Federer in this and other Grand Slam tournaments? No one knows, but this much is certain: It’s going to be quite fascinating to find out how Federer navigates this uncertain new stage in his brilliant career.