ARLINGTON HEIGHTS, Ill – The conventional handicapping wisdom holds that horses coming back from long layoffs represent a risky betting proposition. Throw the conventional wisdom out the window considering layoff horses trained by Steve Margolis. Of Margolis’s last 26 returnees from a layoff of at least a half-year nine have won, good for a strike rate of 35-percent and a return-on-investment of $3.59. The Margolis-trained Country Day, one of 10 horses entered in the Arlington Sprint on Saturday, hasn’t started since Oct. 28 at Keeneland. That may be a good thing.Country Day could well be favored in the Arlington Sprint, a 5 1/2-furlong turf race carrying a $100,000 purse. The trainer’s layoff record is there for all to see, and Country Day has done well in limited previous grass action. An even third over soft going in his turf debut, he was beaten less than a length by an in-form Chamberlain Bridge in his next turf try, and Country Day’s last start before his layoff produced a clear turf win over high-end Keeneland allowance foes.Country Day, Margolis said, hasn’t raced since then because of a leg fracture that required surgery to repair, but the 5-year-old horse has been working steadily at Churchill since late May.“We tried to get him into a money allowance at the end of Churchill, but unfortunately they didn’t use it,” Margolis said. “As a backup, we went into this race.”Plan B should work fine. There are no obvious killers in Saturday’s race, and jockey Shaun Bridgmohan might be able to work out a nice stalking trip.Birdie Beats Par could prove a formidable foe, though he is a 3-year-old facing older rivals in his stakes debut. Birdie Beats Par has won 3 of his last 4 starts and was especially impressive last out in his first turf race since moving to the barn of trainer Tom Amoss, winning a second-level Churchill allowance by more than four lengths under Bridgmohan. Birdie Beats Par, well drawn on the outside, should hook up with contender Jr’s Exchange on the front end. Jr’s Exchange, 3 for 4 on the grass, was a troubled fifth at Tampa Bay in his only prior stakes start. Jr’s Exchange is one of two entrants from trainer Gerald Bennett, who also has turf-debuting Capitol Appeal.Yankee Injunity won this race in 2009 but is just 1 for 11 the last two calendar years. Trainer Bret Calhoun won the 2010 running with Chamberlain Bridge and this year tries Chief of Affairs, who finished off the board in his lone prior grass try.