Not only does McDonald's stat show the enormous demand at the highest level for services but provides him with an unprecedented insight into today's field, especially as he is the regular jockey favourites Zaaki and Verry Elleegant.
McDonald says every horse in the field has its strengths but also a potential chink and the winner will be the one whose chink isn't exposed.
"I have been through all of their form and know most of them pretty well and they all have a weakness or something people at least think is a weakness," McDonald told the Weekend Herald yesterday.
"Zaaki and Verry Elleegant were beaten last time so that is a start," says McDonald.
"As good as the three-year-olds are they aren't proven at the 2040m, Probabeel would hate if it got wet, Mo'unga and Dalasan were both beaten in a weaker field last time.
"So they all have reasons why they can get beaten and it will be the one who is spot on and gets the right type of track conditions and run it likes on the day," he said.
"But after going through them all I keep coming back to Zaaki and Verry Elleegant. They are the two who are proven at this level time and time again and are just great horses," added the star ex-pat Kiwi hoop.
Although both were beaten last start, probably on tracks firmer than they really like, McDonald says it is easier for the best horses to back from setbacks and defeats, which is how they get to be the elite.
"A horse like Zaaki, everybody was potting him when he ran third last start whereas if he wasn't that good people would think it was an okay run," said McDonald.
"And let's not forget, he easily beat Probabeel the start before at Sandown.
"It doesn't take much to get beaten in the best races but it also doesn't take much to bounce back.
"I think he will bounce back and he is the one to beat.
"But the mare [Verry Elleegant] has to be tough because this is what she does week-in, week-out, race tough in these big races.
"I am not put off by what happened to her last start and she will still be very hard to beat."
Showers forecast for Melbourne last night would help both favourites in the great race.
But what could aid Zaaki even more is the potential he rolls forward to the lead and gets a head of steam up from the 800m, the way the top (former) English horses love to race.
If he does that and gets into a rhythm he is going to be incredibly hard to catch, especially as the other favourites could be coming from midfield and wide.
The chances of Zaaki leading and trying those tactics were boosted when Callsign Mav's trainer John Bary declared yesterday he doesn't want the big Kiwi in front, preferring Luke Nolan settles him off the speed.
Nobody will be watching the early morning track reports more closely than the team behind Probabeel, who are hoping they have dodged a weather bullet with the rain expected for Melbourne not having come before last night.
The small field and a dry track would give her a real chance as she and Anamoe are the only ones in the field with last-start winning form on Australian soil.
Her brave win, over Zaaki, in the A$1m Might And Power last start showed Probabeel can beat the best at 2000m but she is unlikely to get a tempo as friendly today.
Still, she is a mare in form and has Victoria's rider of the spring in Brett Prebble on board.
● Cambridge stablemates Elephant and Rhinoceros clash in the A$300,000 Crystal Mile at The Valley, with Elephant the warm favourite to continue a wonderful summer for trainers David and Emma-Lee Browne.
Cox Plate picks
A$5 million, 7.10pm
1: Zaaki
2: Anamoe
3: Probabeel