In certain cases we can merely speculate, trusting that more will be revealed than the expertise of the groundstaff in running the tarpaulin.
Recalling the headline in these pages a year ago - "Expect the unexpected" - and bearing in mind the vagaries of the French Open only weeks ago, prognostication is attempted with even less conviction than usual, which is saying something.
Clearly, Henman has not peaked too soon leading up to the championships, which is probably just as well considering that the 22-year-old from Oxford has been built up as the best thing since Fred Perry.
Henman's advance to the quarter-finals last year was impressive, and he continued to prove himself a contender of genuine quality at the highest level of the sport until forced to undergo surgery to his right elbow in March.
Although Henman's recent form has oscillated between erratic and disappointing, his general demeanour has disguised anything deeper than a dip in confidence. At No 14, he is the nation's first seed in the men's singles since Buster Mottram in 1982, and his match today against the Canadian Daniel Nestor is scheduled to launch No 1 Court.
Wisely, Henman will be thinking no further than the business in hand, leaving the media to conjure whatever they will of a possible meeting with Richard Krajicek, the defending champion, in the fourth round.
Thunder is the confident forecast for the Centre Court match between Greg Rusedski, the British No 2, and Australia's Mark Philippoussis, both of whom endorse rackets by Thor, regardless of the respective logos.
Whoever remains standing after the duel of the world's fastest servers - "Scud" Philippoussis 142mph, Rusedski 139mph - could emerge as a possible threat to Goran Ivanisevic, the No 2 seed, in the quarter-finals.
"Mentally we all know Goran can be a little bit up and down," Sampras says. "Once he works on that, is a bit stronger mentally, one year he's going to win a Wimbledon because of his game. It's up to him."
Your correspondent's sentiments precisely. The snag is that Ivanisevic, 25, might run out of years before he finds the belief. Perhaps his time has come.
Krajicek found last year that he could return serves as well as serve them, a discovery which inspired the Dutchman to an emphatic triumph. He is not the type to lack confidence as the defending champion. Unlike Krajicek, those who complain about uneven bounces at Wimbledon were probably oblivious to last year's Centre Court streaker.
Along with Philippoussis, the Aussies have another strong challenger in the athletic Pat Rafter, and Russia's Yevgeny Kafelnikov may be due a run after narrowly losing to Henman in the first round last year.
Sampras has experienced a lean time by his standards since winning the Australian Open in January, but the three-times champion is not a player to bet against. The American has had his share of injuries, illnesses and emotional turmoil while endeavouring to run smoothly during the past few years. However, as his coach, Paul Annacone, points out, "When you have a Ferrari, there's not a lot of rebuilding to do."
It is possible that Sampras will meet Boris Becker in the quarter-finals. The popular German's longevity can be gauged by the number of top men he has seen come and go. "I was trying to adapt every couple of years to the new players and the new No 1s," he says. "I started with McEnroe as No 1, then Lendl as No 1, then Edberg as No 1, then Courier as No 1, then Sampras as No 1. And in the meantime I was No 1 for a little bit, too.
"So I've lived through many No 1s, and I was trying to learn from each one, their weapons and what made them so good. That is why my career is so long, because I was able to learn from all those players."
The women's singles is bound to be influenced by the Steffi Graf effect. The absence of the seven-times champion will cause some players to re- evaluate their prospects while others may be encouraged to play without bothering their heads.
Jana Novotna, asked on one occasion why she had never won a Grand Slam title, said that Graf had always been in the way. "As soon as I saw that Steffi had pulled out I just knew somebody would remind me about that," she said. "I was joking at the time, but nevertheless Steffi was always there to stop me winning the big tournaments, and not only Grand Slams. I will do my best."
So, too, will Arantxa Sanchez Vicario, denied by Graf in the past two finals, and Monica Seles, who was beaten by Graf in the 1992 final and has never justified herself at the All England Club.
Hingis, who lost to Graf on each of her two previous appearances in the main draw, may have gained the confidence necessary for success on the lawns as a consequence of her triumph in the doubles with Helena Sukova.
Rested after losing to the inspired Iva Majoli in the final of the French Open, Hingis has the class to win at 16, and Ivanisevic is overdue his moment of glory.
Incidentally, the first ball to be struck on No 1 Court was served last September by Professor Bernard Neal, a committee member, to Peter Jackson, chairman of the Wimbledon sub-committee which has master- minded the long-term plan. They played three rallies.
Then on came the chairman's four for a one-set doubles. The chairman, John Curry, played with Mike Hann, and Roger Ambrose with John Barrett, the BBC commentator. "The court was beautiful," Barrett said, "hard and true, flat as a pancake."
The first ace was served by Ambrose. Barrett was guilty of the first double-fault. "I'm claiming it as a record," he said.
TODAY'SORDER OF PLAY
M Craca (Ger) v R KRAJICEK (Neth)
M PHILIPPOUSSIS (Aus) v G Rusedski (GB)
C Rubin (US) v A Kournikova (Rus)
No 1 Court
T HENMAN (GB) v D Nestor (Can)
M Stich (Ger) v J Courier (US)
R McQuillan (Aus) v M SELES (US)
D Pescariu (Rom) v G IVANISEVIC (Croa)
I MAJOLI (Croa) v M Diaz Oliva (Arg)
A J COETZER (SA) v A Fusai (Fr)
Y KAFELNIKOV (Rus) v J Marin (Sp)
S Bryan (US) v C MOYA (Sp)
J Gimelstob (US) v G KUERTEN (Br)
N Sawamatsu (Japan) v S Smith (GB)
V Williams (US) v M Grzybowska (Pol)
A L Richardson (GB) v S Duran (Sp)
J Tarango (US) v R Gilbert (Fr)
S Cacic (US) v A Frazier (US)
J K Wiesner (Aut) v J Kandarr (Ger)
M Maleeva (Bul) v J M Pullin (GB)
J Delgado (GB) v J Golmard (Fr)
N Marques (Por) v M Lee (GB)
S Appelmans (Bel) v R Simpson (Can)
A Pavel (Rom) v F Dewulf (Bel)
K Po (US) v K A Guse (Aus)
F Lubiani (It) v S Pitkowski (Fr)
N Kulti (Swe) v M Sinner (Ger)
M Endo (Japan) v G Leon Garcia (Sp)
A Clement (Fr) v L Milligan (GB)
M Charpentier (Arg) v C Pioline (Fr)
A Grossman (US) v K Brandi (US)
J Frana (Arg) v M Damm (Cz Rep)
N Lapentti (Ec) v F Clavet (Sp)
M Tu (US) v I Gorrochategui (Arg)
B Schett (Aut) v A Carlsson (Swe)
J Viloca (Sp) v M Goellner (Ger)
A Sugiyama (Japan) v Y Basuki (Indo)
J Watanabe (US) v M Serna (Sp)
B Ellwood and P Tramacchi (Aus) v B Behrens (US) and C Haggard (SA)
H Arazi (Mor) v R A Reneberg (US)
K Carlsen (Den) v E Alvarez (Sp)
F Perfetti (It) v M Sanchez Lorenzo (Sp)
D Dilucia (US) and R Smith (Bah) v R Lavergne and S Simian (Fr)
E Makarova (Rus) v T Panova (Rus)
S Stolle (Aus) v C Woodruff (US)
E Martincova (Cz Rep) v L M Raymond (US)
C Torrens-Valero (Sp) v G Pizzichini (It)
F Fetterlein (Den) v J Novak (Cz Rep)
N Dechy (Fr) v L Courtois (Bel)
L Richterova (Cz Rep) v T Tanasugarn (Thai)
T S Jones (US) v L A DAVENPORT (US)
J Bjorkman (Swe) v C Wilkinson (GB)
K Boogert (Neth) v B Paulus (Aut)
M Woodforde (Aus) v L Paes (Ind)
L Roux (Fr) v B Steven (NZ)
M Maruska (Aut) v A Gersi (Cz Rep)
S Huet (Fr) v J Stark (US)
J Kruger (SA) v S De Ville (Bel)
D Chladkova (Cz Rep) v S Kleinova (Cz Rep)
D Rikl (Cz Rep) v D Vacek (Cz Rep)
M Saeki (Japan) v P Hy-Boulais (Can)
M Tebbutt (Aus) v J Sanchez (Sp)
H Nagyova (Slovak) v I Spirlea (Rom)
W FERREIRA (SA) v S Draper (Aus)
L A Woodroffe (GB) v P Schnyder (Swit)
O Burrieza (Sp) v J Stoltenberg (Aus)
D Norman (Bel) and K Thorne (US) v R Koenig (SA) and A Rueb (US)
M Norman (Swe) v L E Herrera (Mex)
E S H Callens (Bel) v P Suarez (Arg)
A Olsza (Pol) v L Nemeckova (Cz Rep)
l Seeds in CAPITALS.
2.15 start on Centre Court and No 1 Court; 12.0 noon on other courts except where stated.