Some 17-odd years ago when BRIS started their Insider Picks and Power Plays I did an ROI study of all the Power Play Angles (HotJockey, BlueChipPowerPlay, HorseForCourse, etc.) that was published in Barry Meadows' handicapping periodical. My sample was the Oaklawn meet of '98. The ONLY Power Play Angle that showed a positive ROI (12-15% winners, 20%+ ROI, if I remember correctly) was CLOCKER SPECIALS in MSW or MdcL dirt sprints. I have used that angle ever since, focusing on 1st or 2nd time starters, mostly in the Midwest. (OP,LD, Rem, and the Texas tracks mainly) Anectdotally, I have used the angle profitably ever since, the last time being last night at Indiana Grand with Brothers Dryden at 10-1 in the 4th. (The other Clkr Spcl in the race, Torazo, finished last at 12-1 and was vanned off the track.) I bet them both to win and cashed with Brthrs Drydn.
The Clkr Spcl is unique because it ranks all workouts on a particular day at a particular track at a specific distance for horses of the SAME AGE. It is the only real value added statistic on the whole sheet. I makes sense that it works best at medium level tracks in the midwest, because the plethora of clockers on the coasts usually smoke out a good thing and the punters bet it appropriately. But, in the midwest, statistical workout standouts fly under the radar and are under bet. Given this board's focus on figs, I expect that I will continue to catch good odds on maiden CS's even though I've now exposed the angle to the game's sharpest bettors.