Nick Bollettieri: Make no mistake: this Williams sister is heading for the final

The Wimbledon files

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Today's big match: Serena Williams v Petra Kvitova

Let's cut to the quick: the young lady from the Czech Republic is going to be overwhelmed by Serena Williams today and lose in straight sets. Kvitova is a banger: she hits the ball very hard and has a decent first serve but that's about it. She really should have lost her quarter-final against Kaia Kanepi, and had let-offs when she was match point down in that three-setter.

This is definitely the crowd-puller of the afternoon because of the potential for the upset by an unseeded outsider of the reigning champion. Upsets are always possible, of course, for reasons we cannot predict, like an injury or a freakish loss of form by a favourite. But there's nothing in this pair's history, abilities, form or talent that suggests an upset.

Kvitova and Serena have met just once before, at the Australian Open earlier this year, where Serena took care of business in their second-round match-up in the manner you'd expect: two and one.

Kvitova's second serve is attackable. Serena will take any short ball and rip it up. She'll also come in quite happily.

When we consider why Serena is such a fearsome opponent, we note her great physical shape and movement. Her forehand has got that big swing, bigger than you'd think is helpful, but with such strong foundations she gets away with it.

On the backhand, Serena and her sister Venus have the quickest turnbacks in the game: watch for that hip and shoulder rotation and way the racket is positioned for the ball. Serena's got that powerful serve. Her second serve is not attackable either. She's comfortable at the net. In all, she is stronger, fitter, quicker, more versatile, and also has the mental advantage of having been here so many times before.

Kvitova is not that rare in being unseeded and in the semis: she is the 10th unseeded player to reach the last four since 2001. She is the last remaining leftie in the draw, but leftie players have not thrived here for a while. The last leftie winner was Martina Navratilova, 20 years ago, and there hasn't been a leftie Slam finalist since Monica Seles at Roland Garros in 1998.

Kvitova will jump into the world top 30 for the first time whatever happens. She trains in the same club in Prostejov, Czech Republic as Tomas Berdych, and this is the first time she's been beyond the fourth round of any Slam.

She's had three wins against top 10 players in her career, including beating Venus Williams in Memphis two years ago. There won't be any family business on Serena's mind today, though, apart from wanting to make sure that a Williams reaches the final.

Williams v Kvitova

How they match up:

American Nationality Czech

28 Age 20

Palm Beach Residence Fulnek

1995 Turned pro 2006

Right-handed Plays Left-handed

5ft 9in Height 6ft

No 1 World ranking No 62

36 Career titles 1

$31.2m Career prize-money $637,000

W55 L7 Wimbledon record W5 L2

Winner (3 times) Wimbledon best SF (2010)

1-12 Odds 12-1

Head-to-head: Williams leads 1-0

My prediction: Serena in two

Coaching report: Roger Federer v Tomas Berdych

In these pages on the opening day of the tournament, I said this was the most wide open Wimbledon I've known, partly because Roger Federer's years of invincibility are over. I also wrote: "If there's one player I think could cause Federer problems in the top quarter, it's Tomas Berdych." Then I outlined some of Berdych's recent achievements. So yesterday was a surprise, but not a big shock for me.

I watched the match and can point to seven things that stood out in Federer's demise. First, he looked completely out of sync with himself. By that I mean his movement was not as fluid as his best and his timing was off. Roger himself told us in the post-match interview that he's had a slight back and leg injury and maybe that explains it – but only partially.

Second, Roger made an atypical error of strategy in response to an approach by Berdych to serve into Roger's body on the deuce side. Roger can choose to hit his return forehand or backhand but erred in hitting backhand, taking him off the court, and leaving it wide open for Berdych to attack.

Third, Roger's sliced backhand has hurt him throughout the tournament and it was off again yesterday. Fourth, on return of serve, two hands are going to give him a better chance than the one-handed backhand and whoever you are – genius or no – you need not just to adapt but to realise you need to adapt. The power of the game these days has changed things.

Fifth, Berdych is in tremendous physical shape. The guy should model cycling shorts because he's got incredible thighs. He has obviously spent a lot of time in the gym – and building that core strength. Sixth, related to the previous point, was the power of Berdych's forehand. He hit an amazing amount of winners – 51 in the four sets, 16 in that final set alone – and his big forehand weapon provided most of them.

Seventh, Berdych kept a better check on his emotions than Federer. Amazing.

Win a week at my academy

Ritesh Gupta predicted the right scoreline of the Nadal v Soderling game, so goes into the hat to win a week at my Florida academy. To enter today, do the same for Williams v Kvitova, plus sentence on the manner in which your pick will win. Email entries to n.bollettieri@independent.co.uk

If the prize is for a child, parent(s) or guardian(s) must accompany at your own expense. Winner must arrange travel.