A smaller catalog and optimism over Aqueduct’s long-awaited gaming machines could help Fasig-Tipton’s Saratoga select yearling sale edge upward this year. But the Aug. 8-9 auction probably will continue two familiar trends: highly selective buyers and conservative spending at the top of the market. And stock market jitters over a possible double-dip recession and European debt problems might put some buyers in a bearish mood.