Chasing a first Group One win has been causing trainer Ken Keys some sleepless nights.

Keys has the clear-cut favourite Rich Enuff aiming for a fourth straight victory in Saturday's $1 million Caulfield Guineas.

More importantly, the horse will bid to deliver Keys an elusive Group One success after 30 years training.

Keys is both confident and nervous as the race approaches.

"I haven't stopped playing things through my mind," Keys said.

"I lie awake at night thinking about the race."

Rich Enuff is stepping up to 1600m for the first time and while there are some pundits wondering whether he will run the distance, Keys and jockey Michael Rodd are in no doubt the son of Written Tycoon will handle the trip.

Keys points to the colt's half-brother Lightenuff, by Lago Delight, who was successful at 2000m.

"We could be proved wrong on that, but in our mind we have no doubt he will run it," Keys said.

"He relaxed the other day. Michael (Rodd) made the comment that he was asleep from the 800 to the 500 and he was scared that he had no horse under him.

"His half-brother Lightenuff won at 2000-metres, so on that score it doesn't bother me."

Rich Enuff showed his class when he made it three straight wins to take out the Caulfield Guineas Prelude (1400m) on September 28 and the colt rounded off his preparation for Saturday's race with a strong gallop at Cranbourne on Tuesday morning.

"Michael came down and rode him. He was happy and I was too," Keys said.

"He went over 1200 (metres) in evens and a strong last half-mile, and he needed it.

"It was a good clean up for him as he hadn't had a proper gallop since he last raced."

Keys knows the Guineas will be a tough race.

He labelled the Peter and Paul Snowden-trained Shooting To Win and Looks Like The Cat, runner-up at his past two starts to Rich Enuff, as logical dangers.

"You could make a case for every horse in this race," Keys said.

"Obviously the Snowdens' horse looked pretty good the other day and the `Cat' looks like he'll be suited over the extra 200 metres also.

"They'll be going forward and I guess we will be also.

"It's now who can run out the mile and I'm confident we can."