The Robert Smerdon-trained Ability has started to fulfil his potential and puts his unbeaten run this preparation on the line when he faces his biggest test in the Group Three Bletchingly Stakes.

Craig Williams, who takes a three-win lead in the Melbourne jockeys' premiership into the season's final city meeting on Saturday at Caulfield, was aboard for Ability first two starts this campaign.

He is happy to get back aboard after missing the Listed All Victorian Sprint Series Final on July 8 through suspension.

"Even though he goes to weight-for-age you wouldn't be jumping off a horse that's three for three," Williams said.

"I thought he was a Group horse at the start of the preparation so if he lives up to my expectations and Robert's assessment of him, he's going to be competitive in what looks to be a very competitive weight-for-age race."

Ability, who races in the colours of the late Phil Sly, won three of his first 12 starts.

He has returned this campaign after a lengthy break, a gelding operation and the removal of a bone chip, and put three impressive wins together to rise through the grades.

Smerdon said the sprinter appeared to have maintained his form going into the Bletchingly (1200m) but also said it was another step and his performance would have a bearing on spring plans.

It will be Ability's first test at Group level and his opposition includes Monash Stakes winner and Group One placegetter Supido and multiple Group One winner Lankan Rupee.

"If he doesn't measure up, he can come back (in grade). There's lesser races for him," Smerdon said.

"It's not a bad field, which is good.

"After last start I was thinking I might back off him and send him to the water walker and find something in the spring.

"But I kept him in the stable for a few days and thought 'there's a race in front of us, what am I waiting for? Just take what's there rather than wait for something else and take the chance of other issues'.

"So we said if we were happy with him in between and like the way things line up, which has happened, then we'll have a go."