Changes to ratings bands for city and provincial races will be implemented from the end of the Ascot season as Racing and Wagering WA attempts to combat small field sizes.
Revised bands for three-year-old and upwards races in the city and provincial areas were agreed to by industry representatives at a Thoroughbred Racing Consultative Group meeting this week.
Programming for two and three-year-old races will also be reviewed and changes are likely to be submitted at the next TRCG meeting in May.
Changes to the three-year-old and upwards races include: 54-64 races changed to 52-64; 57-68 changed to 56-68; and 62-74 changed to 60-plus.
The 68-plus, 74-plus, 80-plus and 86-plus races will each be dropped two ratings points.
RWWA chief handicapper David Hunter said the adjustments had been made to produce bigger fields at Saturday meetings.
Prime metropolitan meetings last month were plagued by small field sizes. Programming changes will be effective from April 27.
"The changes will hopefully get more horses to Saturday meetings quicker and throughout the year," Hunter said.
"Open three-year-old races on Saturdays have been a problem so we need to review the three-year-old program. We need to encourage owners to race their three-year-olds on Saturdays rather than at provincials and midweeks.
"We also need to look at whether we need as many two-year-old races in January as the industry doesn't seem to be crying out for them during that month."
RWWA handicappers will start recording a merit-based rating for each performance.
Hunter said the merit-based rating would give handicappers a better guide to moving horses down the system if they were running well below their rating.
It would also help them identify poor-quality races where a smaller penalty could be appropriate.
Hunter said he was against capping a number of ratings points given to horses for winning.
"It's not just as simple as putting a cap on penalties. There are plenty of holes in that theory and it puts black-type races here in danger," Hunter said.