The evidence so far in the Embassy World Championships suggests Hendry's travelling companions are being bombarded with noise one trip and silence the next, because the five-time champion's form is fluctuating like the weather. Good and average, it is difficult to get a decent barometer reading.
So far it has not mattered. At The Crucible Hendry would intimidate opponents if he turned up on a stretcher and yesterday he reached the quarter-finals, beating Gary Wilkinson 13-7, without nearing the heights he normally touches in Sheffield. Conventional wisdom has it that if you give the Scot a chance the frame is gone; this time it is sometimes taking two and three visits to the table.
The first frame yesterday was a cameo of his performances so far. Ahead 10-6 overnight, he quickly surged forward with a break of 30 but then missed a black that was easy by his standards, and it required a reciprocal error from Wilkinson for him to prevail.
Breaks of 105 and 43 carried Hendry over the line - not without further mistakes it should be added - although whether his form is enough to take him to a fifth successive title is debatable.
"I'm not playing well enough to win it," Hendry agreed. "I don't know why because I'm cueing well but it's just not happening. It had better happen soon or else I'll be heading back north on the M1."
No player could represent the transitory, fickle nature of success better than Dave Harold. Before Christmas he could barely pot a ball, but since then he has reached two semi-finals and now his first quarter-final at The Crucible.
"I don't know why my form changed," Harold, the 13th seed, said. "I'm doing the same things, practising just as hard, but for some reason I'm winning matches where I was losing them. It's a confidence thing, I suppose." Confident or not Harold, from Stoke-on-Trent, still estimated that he was playing 28 points a frame worse than in his first-round match.
But the Liverpudlian Rod Lawler was even further below par. He had defeated the fourth seed, John Parrott, last time out but succumbed quickly to Harold yesterday, slumping from 11-5 overnight to 13-6 in 45 minutes.
John Higgins ended the first session of his all-Scottish clash with Alan McManus by striking withna cear advantage a vital psychological blow. McManus looked certain to reduce the arrears in the eighth frame, but instead of trailing 5-3 he found himself 6-2 adrift overnight as Higgins made a masterly 73 clearance from 71-0 down.Reuse content