Purdon is adamant how his quartet's chances and tactics relate to each other's chance doesn't even come into his thinking.
"We can't drive to beat Locharburn and we wouldn't do that anyway," he says matter-of-factly.
"I don't tend to tell my drivers too much anyway, but I'll tell them how the horses have been working and what their strengths are and then they can decide what to do when the gate leaves.
"Like everybody else I have been really impressed by what Locharburn has been doing and if he begins well he could well be the leader.
"But I am sure the speed will be on and our horses will get their chance."
Considering Locharburn seems comfortable as a 2:40 clip for 2200m Purdon's leading pair (based on draws) of Bettor Offer and Sky Major look well placed tucked away on the markers waiting for their moment to swoop.
It was exactly that sort of run that saw Sky Major slingshot to his Jewels win in June and if Tony Herlihy can repeat that master drive he looks the greatest danger to Locharburn, whose relentless style will make it hard for those coming wider.
"I suppose Sky Major is the best of mine but not by much, because Bettor Offer has done a super job in his short career.
"Whereas Maxim is as good as them but he might be forced to come wide and that is a hard way to win in this type of race."
Add in Alleluia and Isaiah, the unbeaten Ultimate Major and a group one winner in Cyclone Prince and the race is a stunner. But it will take something special to beat Locharburn.
While the Purdon-Herlihy combination could need some luck with Sky Major, they hold the key to today's other richest race, the $160,000 Sires' Stakes Championship with Ideal Belle.
She has emerged from nowhere to already be the national 1700m record holder following her 1:54 mile rate for 1700m last start, even after scrambling early and almost galloping.
"She had a slight issue with her hopple shortener that night," said Purdon.
"And after the time she went I gave her a few easy days but she worked very well on Saturday morning so she should be spot-on."
Ideal Belle has shown sufficient gate speed to suggest she can hold the inside running into the first bend and then it wouldn't surprise to see her do exactly what she did last start, trail Raksdeal.
That free-going Southland filly would deter too many attackers and if Ideal Belle is sitting on her back turning for home she is the one to beat because that could also tuck key rival Venus Serena away in traffic.
The latter has been the best of this crop for the past eight months and if they go crazy and she gets a gap at the 400m mark she might still be too good.
However, she could struggle to give Ideal Belle, and even Raksdeal, too much of a start at the top of the straight.
Later on the day, Purdon hopes Pembrook Benny can stay close to Easy On The Eye to test him in a Manukau Cup which could be decided by where the big names settle.
Premier day of action at the Park
* Alexandra Park holds its only premier day meeting of the season today.
* It has drawn a strong card, with $490,000 up for grabs in 70 minutes in
the middle of the programme.
* Champion trainer Barry Purdon holds a huge hand in three of the day's
best races.
* The 11-race card starts at 12.15pm.
* Recently-retired trotting hero I Can Doosit will be honoured after leading out the field for the National Trot.
