The Keeneland September yearling sale, annually a test of the yearling market in North America across all levels, began its run Monday in Lexington, Ky., with sessions set to continue through Sept. 25. Fireworks at the top end of a highly selective market seemed a certainty. This auction has produced at least one million&#45;dollar yearling every year since 1995, with 11 at last year&rsquo;s edition alone. Purchase price is no guarantee of success, however, in the highly speculative Thoroughbred market. While price is often based upon the residual value of a horse as a future stallion or broodmare, the majority of recent sale&#45;toppers have not come close to approaching their commercial price on the racetrack. The only graded/group winner to top Keeneland September in the last decade is Mohaymen, who co&#45;topped the sale at $2.2 million in 2014 and has earned $984,517 for Shadwell. A son of two&#45;time reigning leading sire Tapit, Mohaymen won the first five starts of his career, including Grade 2 scores in the Nashua, Remsen, Holy Bull, and Fountain of Youth, before losing four straight. Air Vice Marshal, who co&#45;topped the 2014 sale with Mohaymen, is a Group 2&#45;placed winner for Coolmore, which also found success with 2007 sale&#45;topper Dunkirk ($3.7 million). A son of Unbridled&rsquo;s Song, Dunkirk won his first two starts, finished second in the Florida Derby in just his third start, was 11th in the Kentucky Derby after stumbling at the start, and rebounded to finish second in the Belmont Stakes. Heyaarat ($1.65 million, 2012), Powerful ($1.4 million, 2011), and Meydan City ($11.7 million, 2006) were also winners. Treaty of Rome ($2.5 million, 2013) is winless in three starts, most recently running in August 2015. Mr. Besilu ($4.2 million, 2010) went winless throughout his career, as did Storm &lsquo;n Indian ($2.05 million, 2009) and Keeneland Breeze ($1.5 million, 2008). Last year&rsquo;s sale&#45;topper was Tapit High, who went to Mandy Pope&rsquo;s Whisper Hill Farm for $2.1 million. He does not currently show any published workouts.