12/19/2001 1:00AM

Castlebrook ready for the Stage Door Betty


MIAMI - Castlebrook breezed an easy half-mile in 49.60 seconds here on Wednesday. Trainer Bill Kaplan pronounced her fit and ready to accept her highweight assignment of 118 pounds for Saturday's $100,000 Stage Door Betty Handicap.

Castlebrook has been the leader of the local filly and mare handicap division since winning 4 of 5 starts, all stakes, during a 12-week period from June 15 through Sept. 15. A 4-year-old filly, Castlebrook dropped her last two starts, finishing fourth after breaking poorly in the Shocker T. Handicap and third when turned back to 6 1/2 furlongs for the U Can Do It Handicap on Nov. 24.

"I sprinted her last time just to keep her sharp," Kaplan said on Wednesday. "I knew she'd drop back and make up ground at the end. She's really doing very well at the moment and I expect her to run big on Saturday, although this race comes up a little tougher than some of the others with De Bertie in the lineup."

Castlebrook, a daughter of Montbrook and Medieval Tears, has earned more than $135,000 for owners Herb and Ione Elkins this season.

Best of the Rest and Sir Bear work

The two top main track handicap horses stabled at Calder, Best of the Rest and Sir Bear, also worked on Wednesday. Best of the Rest went five furlongs in 1:01.80, Sir Bear a half in 47.80 seconds. Best of the Rest is pointing for the $100,000 Fred Hooper Jr. Handicap on Dec. 29, while Sir Bear is expected to make his next start in Gulfstream Park's Skip Away Handicap. They are both using those races as stepping-stones to the Grade 1 Donn Handicap on Feb. 9.

"He's doing great right now, knock on wood," trainer Eddie Plesa Jr. said of the talented but fragile Best of the Rest, who won the Spend a Buck and King Rex handicaps in his last two starts.

The Hooper is one of four stakes to be decided on the Dec. 29 Grand Slam II program. It drew 14 nominations, a list that also includes Grade 1 winner Outofthebox.

The strongest of the four Grand Slam races could be the Grade 2 W.L. McKnight Handicap. Trainer Bobby Frankel has committed to shipping Super Quercus, winner of the Grade 1 Hollywood Turf Cup, from California to face a field that figures to include the locally based Mr. Pleasentfar, recent winner of the Grade 2 Red Smith Handicap along with Grade 1 winner Honor Glide.

Accompanying Super Quercus on his trip east will be stablemate Seven Seas, who is among the nominees for the La Prevoyante Handicap, which like the McKnight carries Grade 2 status and will be decided at 1 1/2 miles on the turf for a purse of $150,000.

Long stretch run

There is a change in the entry schedule for Christmas week. Double entries will be taken Friday for Sunday and Monday's programs, while entries for Wednesday, Dec. 26, and Thursday Dec. 27, will be drawn on Saturday and Sunday respectively.

Friday's 12-race program is a likely indication there will be no rest for the already-weary local horse population through the end of the meet with 12-race cards likely to be the rule rather than the exception until the end of the session on Jan. 2. Gulfstream Park opens the following day, which means there will be 14 straight days of racing on the south Florida circuit from Dec. 26 until Gulfstream's first dark day on Jan. 8.