(Germany, aged 33, world No 895)
Tommy's been with us for 20 years now. I remember when he first arrived as a raw 13-year-old.
We put him in a dormitory with some of the other boys but he missed home so badly that it wasn't long before he went back to Germany. When he came back I moved him into my house. He lived with me for a while and was soon playing beautifully. We spent a lot of time developing his backhand, which became one of the best in the game.
Although Tommy got to No 2 in the world and played in one Wimbledon semi-final (he lost to Roger Federer in 2009), two Australian Open semis and three US Open quarter-finals, he's also the unluckiest player in the game. He's just come back after missing more than a year following a fourth operation on his shoulder. Four operations! They should give him a role in ER.
Tommy collects injuries like Imelda Marcos collected shoes. He's broken both ankles and has had to pull out in the middle of Wimbledon three times, once when he trod on a ball in the warm-up. On another occasion he missed Wimbledon because his parents were seriously hurt in a motorcycle accident. If you're buying a lottery ticket, don't ask Tommy to pick your numbers.
After his latest injury I'm sure most players would have called it a day. Tommy, though, is not a quitter. He could be as dangerous as a moose on the loose next week. With that beautiful sliced backhand and aggressive forehand, he can be one hell of a threat on grass.
(Russia, aged 26, world No 3)
Although Vera wasn't at my academy as a youngster she's spent a lot of time with us over the last three or four years. We get on well, but she doesn't socialise much. She does her work and that's it.
Vera played in 24 Grand Slam tournaments before she got to a semi-final, but has made up for lost time. She reached the final at Wimbledon and the US Open last year. She's nobody's fool. She's learned a great deal about how to compete. Does she smile? Holy mackerel! When I get a smile from her it's like God blessing me. She's a no-nonsense girl. She doesn't give a damn about anything. It's all business to her. Technically Vera doesn't have a flaw.
She is not the biggest but she moves well, competes well, has a good serve and can volley. My only worry would be if she came up early against a big hitter who attacked her. Just put the ball back in play and Vera will kill you, but she can get rattled under pressure.
(Slovakia, aged 28, world No 25)
Daniela's a super girl, as kind as can be. In the past she's sent me little notes to thank me for the two or three years she had at the academy when she was young. She came back with her coach to see us a couple of years ago. She's a superstar, a real ambassador for our sport. She'll have a wonderful life after tennis.
Her ground strokes are as good as they come, her technique is unbelievable and she's a beautiful volleyer. She played a great tournament at Edgbaston and has done well again this week at Eastbourne.
Daniela got to No 5 in the world eight years ago. I'd love to say she has one more big Grand Slam tournament in her, but if she's to make the second week at Wimbledon I think she has to come into the net more. She hits the ball beautifully from the baseline but with the way the game is played today I think she has to attack more. You can't just stay back these days.
(Russia, aged 24, world No 6)
Maria first came to the academy when she was only nine. She was soon intimidating everybody. Within two or three years all she had to do when she went on court to play girls like Jelena Jankovic and Tatiana Golovin was look at them. They would melt right there on the spot. They were scared to death.
She still comes back to the academy quite often. She was with us a couple of months ago. She's now working with Thomas Hogstedt, who's an excellent coach. I know him well from the time he coached Tommy Haas.
Maria's special. She's great for tennis. She's as competitive as anybody in the history of the game. She knows only one way to play – pound that ball as hard as you can, hit it early, go after your opponent's serve. She also knows how to win Wimbledon.
The last three years haven't been easy for Maria after her shoulder surgery, but she's been serving a lot better lately. Getting that first serve in can be key to her whole game. As she showed in reaching the French Open semi-finals, she's hitting her ground strokes well at the moment. Her movement's good and I really believe she's getting back to where she once was. Most important of all, she's never lost that competitiveness.
(Belarus, aged 33, world No 3 in doubles)
Max (right) has been at the academy for 21 years. He's a great doubles player, but more than anything else he's one of the greatest human beings ever to play the game. His attitude and commitment are an example to everyone.
He's just won his 39th doubles title, in partnership with Daniel Nestor at the French Open. He was runner-up at Wimbledon eight years ago and I would love to see him go one better. The smile on his father Nikolai's face would stretch back to Minsk.
(Japan, aged 21, world No 59)
When Kei first came to us at 14 he couldn't speak a word of English, but he muddled through and learned fast. We now have three of the best young Japanese boys at the academy.
Kei's coach is Dante Bottini, but he also spends time with Brad Gilbert, who's helping him with his strategy in matches. This may sound a strange thing to say when a fast-talker like Brad is involved, but I think the less you say to Kei the better. His movement and judgement are great and he's an instinctive player. Just let him play.
This boy's fun to watch. You never know what the hell's going to happen when Kei's on court. His movement is fabulous and he returns serve well. Just watch him when he gets off the ground to hit that two-handed backhand of his.
Kei needs to get 70 or 80 per cent of his first serves into court. Once he does that, he can be a match for anybody, though he's yet to win at Wimbledon. He had to retire against Marc Gicquel three years ago and in his only other visit last year he drew Rafael Nadal in the first round.
Serena and Venus Williams
(United States, aged 29 and 31, world Nos 26 and 33)
Richard Williams used to bring his daughters to the academy every now and then, but we haven't seen them for a full two years. Working with Serena in particular was one of the highlights of my career.
After the difficult year they've had I think both of them will know they can't just win matches from the baseline. I don't think losing in the second round at Eastbourne this week was necessarily a bad thing for Serena. She had two good warm-up matches. What she will need to do at Wimbledon is serve well.
Venus will have to come forward as much as possible. Her forehand is a little shaky these days but she has great lateral movement at the net.
(Belgium, aged 30, world No 41)
Xavier has been at my academy for 14 years. What a talent. Holy cow, that dude can do it all. He dances like Muhammad Ali and stings like a bee. If you get the chance, just watch his movement and balance as he dances round to hit that beautiful forehand, one of the best in the game. He's a wonderful shot-maker.
So why has a guy who was good enough to make the Wimbledon semi-finals in 2002 not reached a Grand Slam quarter-final in the past nine years? Xavier knows the answer. He told me recently: "Nick, you've been telling me for years, from the time I first came here when I was 16 or 17, that I'm my own worst enemy. I realise that now but at last I'm enjoying playing the game for the first time in my whole life."
Xavier used to doubt himself and let everything bother him. Now that he's having fun it's showing in his game. If he'd had fun before he could have been a top-five player. It just shows that you can have all the talent in the world but you must have the right mental approach to go with it. However, I still think he's capable of pulling off a major upset over the next fortnight.
(Germany, aged 20, world No 62)
Sabine's career has taken more turns than an Indy 500 driver since she came to the academy. Three years ago she beat Dinara Safina in the Australian Open. Two years ago she broke into the world's top 25. Last year she was out for five months with an ankle injury and ended the season at No 179 in the rankings.
She got out of shape and lacked confidence. Her serve is one of her big weapons, but when she's unhappy she can spray double-faults around.
Everyone worked hard to get Sabine back on track and I was delighted when she won at Edgbaston on Monday, beating Daniela Hantuchova in the final. Sabine knows only one way to play: to hit the hell out of the ball. She has a big serve, a huge forehand and a good two-handed backhand. Her movement isn't great, but provided she hits those big serves rallies don't have to last long.
She can be dangerous in the first week because she hits the ball very flat and doesn't back off the baseline. In the second week the court becomes a bit scuffed and the rallies get a bit longer, which won't help her.
Although she's polite, Sabine's not very talkative. But who cares if she's knocking nine bells out of that ball?
(Britain, aged 19, world No 93)
Heather's a real character – funny and feisty, a happy kid who never moans. She's been at the academy for seven years now and is one of the most popular girls around.
Her movement and balance are her forte. She isn't the biggest of hitters, but she's very aggressive. She doesn't just push the ball around. She strikes it on the rise and her ground strokes are impeccable. She hits very good volleys and has a good return of serve.
There's still plenty of room for improvement. She's had a bit of trouble closing out matches and can lose her focus. She has to add to her game. She's not a big girl and I don't think just pounding from the baseline will be enough for her. When she hits returns she has to come up with some surprises.
Having said that, Heather could surprise one of the high rollers. I think she would react very positively if she was playing a big match on one of the show courts.
(Serbia, aged 26, world No 15)
This may sound crazy coming from a guy who's spent most of his life helping players, but I don't think Jelena needs a coach. My advice would be simple: just go out and hit that goddamn ball. I would tell her not to even look at the draw at Wimbledon. She shouldn't even think about who's on the other side of the net.
Jelena spent several years at the academy and I've done some work with her again in the last year or two. She can worry about lots of things, from what the weather's doing to how long her opponent is taking between points. You can see it in her face when she looks up at her entourage. When she does that they should just smile, wave and say: "Hey, how are you Jelena?"
She really shouldn't worry because she has so much talent. She's very athletic, returns serve well and hits good ground strokes. Her backhand down the line is as good as there is on the tour. It makes a big difference if she can get her first serve in. I think she's learning to keep her composure better – and if she does that she's a match for anybody.