The country's premier winter racetracks are experiencing a reversal of fortunes regarding field size.While California has worried about declining field sizes for about two years, Santa Anita Park has created hope this year by attracting 20% more starters per race in its first two weeks. On the East Coast, however, average field size has gone from boom to bust. Gulfstream Park came out of its 2001 season with an 8.2% increase in average starters per race, but this year field size lagged 18% during the first week of racing.Michael Harlow, Santa Anita's racing secretary, attributed the bigger fields to good weather and the highest purses on the California circuit. The meet also was helped by an eight-day break between the end of Hollywood Park's fall meeting and the Santa Anita opening Dec. 26, he said. A larger number of horses were ready to run.Since Dec. 26, Santa Anita fields averaged 9.75 starters per race, compared to 8.18 for the corresponding period a year ago, according to the Jockey Club Information Systems. Northern California's Golden Gate Fields also has seen improvement. Field size is up 3% to 8.14 for the first 41 days of its meet compared with 7.92 a year ago. Any growth is good news at Golden Gate where field size has declined 9% since 1999.Field size is up at Golden Gate because horsemen have left the Northwest tracks, such as Portland Meadows and Emerald Downs, to run for higher purses, according to Richard Lewis, director of racing operations. Golden Gate has 1,300 horses on the grounds and is at 98% capacity.Across the country, Gulfstream Park president Scott Savin is not worried about the abundance of short fields early in the meet."I think the worst of it is behind us," Savin said, noting that the 7.43 average starters per race during the first five days had improved to 8.45 during the sixth and seventh day. Field size averaged 9.43 during the first five racing days in 2001.Hialeah Park's closure of about 1,100 stalls certainly affected Gulfstream, but Savin said an excessive number of races late in Calder Race Course's fall meet, which precedes Gulfstream's, had a greater affect on field size. Calder averaged 11.4 races during the last 15 days of its Tropical meet and Calder-based horses have accounted for less than 40% of starters to-date at Gulfstream when they usually make up half."I think it will take about two or three weeks before the Calder horses recycle and are ready to run again," Savin said. "We probably won't know the affect of the Hialeah closure until about the week of Jan. 21."