David Hayes will make key gear changes to two of his three runners in a plot to win his sixth Group One Blue Diamond Stakes.Hayes has resorted to one his favourite tactics with Evidentia by ordering blinkers for her for the first time in Victoria's premier two-year-old race at Caulfield on Saturday while stablemate Shaaheq will wear winkers for the first time.Hayes will also start Legalistic in the Diamond and he believes any one of his three runners could cause an upset."As usual it is going to

David Hayes will make key gear changes to two of his three runners in a plot to win his sixth Group One Blue Diamond Stakes.

Hayes has resorted to one his favourite tactics with Evidentia by ordering blinkers for her for the first time in Victoria's premier two-year-old race at Caulfield on Saturday while stablemate Shaaheq will wear winkers for the first time.

Hayes will also start Legalistic in the Diamond and he believes any one of his three runners could cause an upset.

"As usual it is going to be very competitive but I am very happy with my lot going in to the race," Hayes said.

"I think they are all improving horses and that is one of the keys to winning the Blue Diamond, having a horse on a rising flame."

Hayes has an uncanny knack of peaking his juveniles for the Diamond and three years in a row he trained the race quinella from 2006 to 2008.

Brett Prebble will fly from Hong Kong to ride Evidentia in the Blue Diamond (1200m) after she won her race debut in Adelaide and finished fourth to Star Witness in the Talindert Stakes at Flemington on January 30.

"I have known she is a blinker horse for a long time but we have waited for the big one before putting them on," Hayes said.

The tactics of adding blinkers to gear has worked many times for Hayes in major races, including in the Blue Diamond four years ago with Nadeem.

Most recently the Hayes-trained All American wore blinkers for the first time when he won the Group One Emirates Stakes at Flemington in November.

Hayes believes winkers are the right gear for Shaaheq and, like blinkers with Evidentia, he has held off putting them on the filly until this week.

"We have been waiting and waiting for the right time," Hayes said.

"We have had the winkers up our sleeve for while and she wouldn't have to improve much."

Shaaheq has finished second at her three starts, including last start when three lengths second to Crystal Lily in the Blue Diamond Preview on January 26.

Dan Nikolic rode Shaaheq in the Preview and will be chasing his third Blue Diamond after wins on Paint (1996) and Redoute's Choice (2000).

Brad Rawiller retains the mount on Legalistic after steering her to a seven-length victory at her only start at Sale earlier this month.

She is $18 in TAB Sportsbet market while Shaaheq is the most favoured of the Hayes team at $15 and Evidentia ($31).

Michael Rodd will ride Talindert runner-up Tricky Tricky ($31) for trainer Leon Corstens.

Blue Diamond Prelude winners Beneteau and Psychologist lead the betting at $3.60 and $4.40.

The final field will be declared and barriers drawn on Tuesday.