Tennis: Wimbledon '92 / Boom time for pair of aces: Ian Tasker on the semi-finalists preoccupied with power

IMAGINE a swinging fast ball from Waqar Younis coupled with the surprise movement off the pitch of a Mushtaq Ahmed googly and you have a rough idea of what it is like to receive a serve from Goran Ivanisevic.

The gangling 20-year-old from Split in Croatia, who plays Pete Sampras in today's semi-finals, has perhaps the finest serve in the power-dominated modern game. In his five matches so far he has delivered an astonishing 133 aces, averaging more than one and a half in each service game.

Stefan Edberg, who was on the receiving end of 33 aces in their quarter-final (and 32 in the final at Stuttgart earlier in the year), was at a loss. 'He just goes out and hits it,' the two-times Wimbledon champion said. 'That's all he does. He bounces it once or twice and then - boom]'

John Feaver, a connoisseur of the serve and deliverer of a Wimbledon record 42 aces in a five-set defeat by John Newcombe in 1976, is another who has been impressed. 'On his day, Ivanisevic is the best server in the world,' the former British Davis Cup player said.

'A fast serve, though, is not necessarily a good serve. Ivanisevic might not win a fast serving competition but he moves it through the air and he can bend the ball both ways like a spin bowler. His disguise makes it difficult to read.'

'The secret of a good serve is getting the body weight behind the ball and developing a fluid motion with the wrists - loosely, like cracking a bullwhip.'

In the past, it was more likely that Ivanisevic's nerve, rather than his wrists, would crack. Although he ran Boris Becker close in the 1990 Wimbledon semi-final (his only Grand Slam semi-final to date) he had developed a reputation for 'tanking' and suffered alarming variations in form, such as when he lost to Britain's Nick Brown here last year.

Bob Brett, Becker's former coach, has had him under his wing for more than a year now and Ivanisevic himself believes he has matured under the Australian's tutelage. 'I was really bad,' he said, 'complaining too much. I was not fighting. I said to myself 'you have to change, otherwise, you cannot go forward'.'

He has recently acquired a forward-looking new manager, Ion Tiriac, who also represents Becker. The Romanian guru-cum-entrepreneur, who can see echoes of Ilie Nastase in his new charge ('the shyness and from time to time the outbursts'), believes Ivanisevic can get even better.

'He undoubtedly has what it takes to be a Wimbledon champion,' Tiriac said. 'He can beat anybody. I don't think anyone can stand his power.

'It's my opinion, though, that he's not using his second serve properly. At the moment it's almost like he does two first serves. The margin for security is therefore not so good. It also means that when he's on, he's completely on. If he can put more spin on his second serve and slide the ball a few more inches on the ground, he'll be even more difficult to return.'

If Ivanisevic, the eighth seed, comes out firing from both barrels today, then Pete Sampras, the No 5, will have his hands full. The only time the pair have previously played on grass - in the final at Manchester on the eve of Wimbledon 1991 - he was brushed aside, 6-4, 6-4, in 44 minutes, winning just six points on the Croat's serve.

However, Sampras is another whose approach has been questioned and who has been answering it in impressive fashion at the All England Club. He has lost just one set to Ivanisevic's four and has also been firing in the aces - 87 so far.

'Sampras certainly has the game,' Tiriac said. 'But Goran has more power. If I had to put money on a Wimbledon winner? As his manager I'd have to say Goran - I'm just sorry I didn't do it at the beginning of the tournament.'

---------------------------------------------------------------------- HEAD TO HEAD: G IVANISEVIC (Croa) v P SAMPRAS (US) (Series level 2-2) ---------------------------------------------------------------------- Year Venue Surface Round Winner Score 1990 Long Island hard quarter-final Ivanisevic 7-6 6-3 1990 Grand Slam Cup carpet quarter-final Sampras 7-6 6-7 8-6 1991 Manchester grass final Ivanisevic 6-4 6-4 1991 Paris indoor carpet round of 16 Sampras 6-3 6-7 7-6 ----------------------------------------------------------------------

---------------------------------------------------------------------- HOW THE BIG SERVERS MATCH UP ---------------------------------------------------------------------- GORAN IVANISEVIC PETE SAMPRAS ---------------------------------------------------------------------- ACES SO FAR ---------------------------------------------------------------------- 17 v L Koslowski 1R v A Cherkasov 10 34 v M Woodforde 2R v T Woodbridge 28 22 v M Rosset 3R v S Davis 15 27 v I Lendl 4R v A Boetsch 25 33 v S Edberg Q-F v M Stich 9 133 TOTAL 87 20 DOUBLE FAULTS 19 66% FIRST SERVES IN 61% 88% SECOND SERVES IN 89% 85% FIRST SERVE POINTS WON 86% 52% SECOND SERVE POINTS WON 57% ----------------------------------------------------------------------