Chris Waller expects weight of numbers to serve him well in the Epsom Handicap but is cautious about his approach to the famous race being a readymade formula for success.

Waller has three runners in the Epsom - a race that has eluded the premier trainer since his stunning rise to the top of Sydney racing.

In market order his trio are the joint favourite Boban, Doncaster Mile winner Sacred Falls and six-year-old Riva De Lago.

Yet past defeats from a similar position of strength will ensure there is no complacency in the Waller yard going into Saturday's meeting at Randwick.

"In the Doncaster one year we had close to the top three in the market," Waller said.

"I went into the race that day thinking I've got a real good chance of winning but it poured rain and we couldn't run in the first three."

Then in last year's Epsom, Waller saddled up two established elite-level horses, the favourite Shoot Out and the 2010 Doncaster Mile winner Rangirangdoo.

They also missed out but Waller still remains the only trainer who has been able to challenge Gai Waterhouse's dominance in Sydney's Group One metric miles.

Since his climb to the top of the training ranks started to accelerate in 2007, Waller is going head to head with Waterhouse in combined statistics from the Doncaster and Epsom.

In that time he has trained three Doncaster winners to Waterhouse's one.

But there is a role reversal in the Epsom with Waterhouse winning the race three times since 2007 compared to Waller whose best return has been placings with Red Tracer and Rangirangdoo.

"This year we've got three genuine chances again and that will help us be a strong force in the race," Waller said.

Numerically, Waterhouse's Epsom hand is the equal of Waller's with three runners on the limit weight - Ashokan, Ecuador and Spurtonic.

Since betting re-opened after Wednesday's barrier draw, Ecuador has carried more support than any other runner with the TAB.

Beaten as an odds-on chance over 2000m at Rosehill last week, Ecuador has been backed from $12 to become firmly entrenched on the fourth tier of betting at $7.50.

The most recent of Waterhouse's eight Epsom winners have been Theseo (2008), Rock Kingdom (2009) and Fat Al (2012).