Leading trainer Chris Waller has called on racing administrators to get back to basics in a bid to arrest Sydney's small field sizes.

The issue has been an ongoing concern in recent weeks and the lack of numbers was again an eyesore at Canterbury on Wednesday when six of the eight races had nine starters or less.

Waller believes the problem is an over-supply of restricted races and says more benchmark events are needed to better cater for the horse population.

"I can't understand why we're going away from the benchmark races," Waller said.

"We brought it in six or seven years ago and it made your horse eligible for so many more races.

"Now, they're bringing in these no-metro win races, no-metro win in the last year races, one-metro win races and maidens. It's just going back to the old days. They've done a complete turnaround.

"There are just too many restrictions."

More concerning is that Waller is starting to look interstate to find better options for his large string of horses.

He already has a base in Melbourne and says Brisbane is becoming an increasingly attractive option due to recent prize money increases.

He pinpointed a 1900-metre race at Canterbury next Wednesday which is restricted to horses who have won two city races, to underline his reasoning.

"I have one horse eligible for it in my stable yet I've got all these stayers," he said.

"And the horse is Beyond Thankful who is racing on Saturday.

"Why not make it a benchmark 75 race? Yes, you might get top weight but at least your horse is eligible."

Waller also believes country horses have little incentive to come to Sydney under the current system.

He would like to see them receive an allowance to make travelling to town an attractive option and believed such an initiative could be monitored so it wasn't "played to advantage".

"These five and six-horse fields suit me - they're easier to win but that's not looking after the industry," he said.

"Benchmark racing is the way to go but we need to give country horses an incentive to come to town too."