Nick Bollettieri's Wimbledon Files: Andy Murray's many happy returns will leave plenty to celebrate

Ivo Karlovic's problem is his backhand. Look for Murray going after it

Andy Murray listens to coach Ivan Lendl during a practice session at Wimbledon yesterday (PA)

Andy Murray could not have asked for a better start to his Wimbledon campaign – and he could not have asked for a better second-round opponent than taking on Ivo Karlovic this afternoon.

The huge Croat, all 6ft 10in and counting, may have a thunderous serve – and on grass that can be a mighty weapon – but Murray is one of the best returners in the sport and the rest of his game is a level above his opponent's. If Murray wasn't such a good returner, different story. But it all points strongly to Murray, that good return and once the rally begins it is only going to favour the Scotsman.

Murray was spectacular in his victory over Nikolay Davydenko on Tuesday night. He looked fit and he looked as if he was enjoying himself – and that's often a key element for your man Murray. Holy cow, up in the box I even saw the flicker of a smile across Ivan Lendl's face. Now that is even more spectacular than what was going on out on the grass!

I like Lendl. I respect the way he played the game and his partnership with Murray has promise. I would say there is a 90 per cent chance of it working out. Murray is not the kind of guy to give backchat or lip to his coach – his mum Judy deserves a lot of credit for that – and I know he respects what Ivan did as a player too. That matters – here is a guy in Ivan that he can buy into.

Having Lendl sat up there in the box makes Murray concentrate more on his game, there is less cussing and moaning. Now it's about the game, and you have to say that game looks in pretty good working order. People talk about players sending out a message with thumping wins like Murray managed on Tuesday, or Roger Federer did yesterday, but you know what? That's bull. Players care only about what they are doing. They will not pay a blind bit of attention to what anyone else is up to until it comes to preparing to face a certain opponent, and then it is down to the coach to sort them out.

A few years ago, Karlovic came down to my IMG Bollettieri academy. He wanted some help with his backhand. "Ivo," I said to him "if only you'd come to me when you were younger I would never have taught you that sliced backhand." That is his big problem, he doesn't hit over the ball and that has probably kept him from being a top player. He trained with me at the academy for a while – he's a kind, gentle soul by the way, a top guy – and he's got plenty; that serve, a good forehand, volleys well.

However, in today's game, with the level so, so high, when you have an area of your game that is at best only neutral, as opposed to being a positive, then the top guys will be ruthless with you. Man, you sure cannot afford for your opponents to know there's an area of your game where you can be caught short. Look for Murray going at that backhand. He will hit on to Karlovic's backhand, attack it and look either to force an error or a slice ball.

The next step for Murray will be to corner him; put the ball down the line and pin his opponent in the corner of the court.

There is no reason a big man cannot have a good backhand, you've just got to look at Juan Martin del Potro or Milos Raonic, and Karlovic has worked on it – he worked damn hard at the academy but it is open to being attacked.

Which leaves him with his one weapon, that mighty, mighty serve. That is his chance, but it will have to be absolutely spot-on, pinpoint and fast because Murray's returning is so good. If Murray neutralises Karlovic's serve, as I expect, then I'm afraid the Croat's chances are slim to none.

Today's big match: Andy Murray v Ivo Karlovic

How they match up

GB Nationality Croatia

25 Age 33

London Residence Zagreb

Right-handed Plays Right-handed

6ft 3in Height 6ft 10in

4 World ranking 59

22 Career titles 4

$20.6m Career prize-money $4.3m

29-6 Wimbledon record 10-8

Semi-finals, 2009/10/11 Wimbledon best Quarter-final, 2009

3 Head-to-head 0

4-5 Odds 4-1

Bollettieri's prediction Murray in straight sets.

Thoughts for the day...

1. Mum's the word in Murray world

There are not many sports to compare to tennis when it comes to parental influence. It's so much more one-on-one than others, particularly the team sports. At practice you see the parents on the side of the court, up close and personal. Could you image that in football? The coach would tell them where to go. They do have influence, and over the years I have seen them all – but I have to say one of the best is Judy Murray. She has to get a lot of credit for where Andy is right now. She knows her sport.

2. And sometimes father knows best, when the name's Williams

Talk of tennis parents and I can't help think of Richard Williams and something he used to tell his remarkable girls when they were six or seven. "Don't think," he would instruct Venus and Serena, "just run and hit the ball."

Truly, sometimes thinking does get in the way.

Coaching report: Heather Watson v Jamie Hampton

Man, I feel so happy for Heather Watson. It was eight years ago that she first came to the IMG Bollettieri academy and I have watched her every step of the way since. Yesterday was a big win – believe me that was a big moment for Heather.

OK, so Jamie Hampton is not a big name and is on the same kind of level as Watson, ranked No 100 in the world compared to Watson's No 103, and playing in her first Wimbledon. But it is not always about the opponent, sometimes it is just about you. Watson has always had ability, what she hasn't always had is the confidence in her ability, and that is why I reckon yesterday could prove such a break for her. It's a big deal – first British woman in the third round for a decade.

Here's what impressed me about her yesterday. She comes out firing, bang, bang, and catches Hampton off balance to sweep the first set. Great – but back comes Hampton in the second. In the past that would have rocked Watson. She would have said to herself "Uh-oh, I'm in trouble here". She didn't, she fired straight back, kept on playing the way she had in the first set. She backed herself and it paid off. Well done, girl.

I went to speak to her afterwards and she said she always felt she could win the match and that is the big difference with Heather Watson 2012 and Heather Watson 2011. She moves well, hits the ball flat, has improved her serve after a lot of work and volleys well. Add to that confidence and belief and we've got ourselves a player.