Nick Bollettieri's Wimbledon files: Smiling Sabine's big guns should make it a blast

Sabine Lisicki has to keep a firm grip on herself (EPA)

On one side the wham-bam, take-no-prisoners smiling assassin that is Sabine Lisicki. On the other is the composed, tireless Pole, Agnieszka Radwanska. What an utter contrast but what a compelling one it makes. Who will win this match of opposites?

Radwanska is seeded four against Lisicki's 23 but I don't see those numbers counting for squat when they step out on that court this afternoon. In fact, I would have Sabine down as the favourite and why wouldn't you? After all, this is the woman who took on Serena Williams in a wild-west shoot-out and won. She also beat Sam Stosur, who was ranked higher, in the third round. She has a game and a half when it is at full power and, man alive, it is at full power right now.

So Lisicki is the favourite but not by much. Radwanska is a canny operator, knows her game and knows how to hang in there. She has played in a Wimbledon final before, so has been at this stage and won through. Last year she beat Angelique Kerber in straight sets to reach her first Slam final – coping with the stage and the occasion, and that is going to be the big thing in this match. Can Lisicki stand tall on the big stage when there is so much at stake?

Sure she can and keep smiling all the way through it as she loads those guns to fire at full blast at Radwanska. I don't think I have ever seen Lisicki playing so well. Staying up after that win over Serena to blast past Kaia Kanepi on Tuesday was a big moment. It would have been so easy to switch down but she kept on firing. Now she has to control those emotions of hers – a Wimbledon semi-final, one win from her first Grand Slam final. She has to keep a firm grip on herself – think the match, Sabine, and only the match.

Last year she beat Maria Sharapova in the fourth round but then fell to Kerber in the quarters. The year before she reached the semis but came up against Sharapova at her cool, dominant best. She should feel comfortable out there – man, she has earned this place in the semi-finals – and if she can concentrate only on the woman standing across the net then she can win.

Radwanska is not one of the big servers. Let's have a look at the figures from their last matches. Radwanska's fastest is 103mph to Lisicki's 118mph, first-serve average 90mph to 104mph, and here's a telling one, second-serve average 71mph to 81mph. Lisicki was sending down second serve aces against Serena and there is not a cat in the hottest part of hell's chance of Radwanska doing that. But what Radwanska does is make sure she keeps that first serve accurate. Her stats there are consistently high.

Radwanska is a player who knows her game inside out and does what she has to do. She is consistent – quarter-finalist at both Slams this year, runner-up here last year after taking a set off Serena in the final. She's a tough cookie. She moves well, has clever groundstrokes, does not hit too many winners but gets the ball back at you time after time after time. Radwanska forces you into mistakes and if she can bog Lisicki down that will cause her all sorts of problems. If the rallies go long it will favour Radwanska.

Lisicki will look to attack – that's how she plays. In fact, that's the only goddam way she knows to play. And that is how she must play if she is to reach the final. She has to get at Radwanska, not let the Pole settle into that steady rhythm of hers – make it bada-bing, not bada-bada-bada-bada-error. Go out fighting and she can go through fighting.

The big match: Lisicki v Radwanska

S Lisicki/A Radwanska

German Nationality Polish

23 Age 24

Bradenton, Florida, US Residence Krakow, Poland

Right-handed Plays Right-handed

5ft 10in Height 5ft 8in

24 World ranking 4

3 Career titles 12

$2.88m Prize-money $12.11m

18-4 Wimbledon record (W-L) 28-7

SF (2011, '13) Wimbledon best F (2012)

1 Head-to-head wins 1

Nick's prediction Lisicki in three sets

Coaching report: You'd want Del Potro next to you in a foxhole

You have to take your hat off to Juan Martin del Potro. Now there is a guy you would want in the foxhole alongside you. That early fall had to hurt, and not only that, it then plays on your mind with every twist and turn out there on a surface where the next slip is just an over-ambitious stretch away. But he stayed on his feet and boy, oh boy, he blasted David Ferrer right out of these Wimbledon championships.

There is much to admire about Ferrer, and so there should be for a guy who is about to become the No 3 player in the world. He runs and runs and runs and then runs some more – he makes his opponent play every single point. But, and this is a big but, in this era of great players he lacks the real killer weapon that means you can win Slams.

Now Del Potro has weapons and he fools you, too. This is one big man, but he moves so well for a guy of that size. Even his movement was better than you would have expected for a guy on one leg! Ferrer tried to move him around but he couldn't get the guy on the run. Del Potro used all his height and all his reach. He has a howitzer of a forehand and a pretty hefty two-handed backhand as well.

And, of course, the serve – that is his winner. Ferrer just could not get it back over the net enough to threaten Del Potro.

I loved the way Del Potro won it in the end with that final rally – it showed both men at their best, with Del Potro firing and Ferrer running.

Del Potro called it the best forehand he has ever played and I am not going to argue with a guy who stands 6ft 6in in his socks. Tip the hat, man, tip the hat.

Thought for the day: Become that mirror man – and make a few changes

So there I was getting dressed the other day. I put on a nice jacket – you gotta dress up for Wimbledon, look the part – and in the inside pocket I found an old note I had written a while back. I like to do that, get thoughts down on a piece of paper, then show them to the guys I work with and leave them to think about it.

This card said: "Look into the mirror and I mean stare into the mirror and ask yourself who you want to be like. What will you do to be like that person?"

Try it – go on, look into the mirror and ask yourself – are you happy with yourself right now? These are powerful things for anybody, not just top sports stars. It's easy to look in the mirror and go: "Oh, I've gotta go to work, I'm not making enough money, I've trouble with my wife, my kids aren't studying."

So do something about it. Guys like Andre Agassi looked in the mirror and decided. Who do you want to be?