The smallest horse in Sydney's premier stable will be aiming for the biggest prize on the first day of The Championships at Randwick.

McCreery is the most favoured of Chris Waller's four runners as he bids to equal the training performances of TJ Smith and Gai Waterhouse with seven wins in tomorrow's A$3 million Doncaster Mile.

"He is the smallest horse in the stable. He weighs 410 kilos," Waller said. "Most horses are around 500 kilos and some 600.

"So he is very small. But he is very effective."

McCreery, who is rated an $11 chance, has a win and a second on heavy ground which he is likely to encounter again, but was a long way from his illustrious stablemate Winx in the George Ryder Stakes after his win in the Gr. 3 Liverpool City Cup.