Most tournaments do not put down a reverse block, it is our preception that since the ball will not come back from wide angles and hook on a pulled shot since there is no wall to hold the ball on line that there is a reverse block.
In reality the shot is probably a 2:1 or 1:1 sport shot.
To play this shot you first need to figure out how far down the lane the oil is. The shorter the pattern the farther right the breakpoint will be, and the longer the pattern, the more inside the breakpoint will be.
Start in warm up by taking your plastic ball and slowly roll the ball up the 10 board with as much side rotation as you can put on it, and watch how far the ball travels down the lane before it hooks. If the ball goes 30 feet (half way) the shot will play off the gutter. If the ball travels 35 ft the shot will play from 5 and out. If the ball travels 40 ft (2/3) the shot will play around 10 if the ball travels 45 to 50 ft the shot will play between 12 and 15 at the breakpoint.
Since you bowl with no thumb, you are probably used to being able to bring the ball back from anywhere. However on this type of a shot you are going to have to play straighter with the boards. This will probably mean using your plastic spare storm ball, or a urethane ball.
You will need to practice playing tighter lines before the tournament, stand on 20 and aim at 13, don't get the ball outside of 10 at the breakpoint. Once you strike move your feet to 22 and aim at 14, then 24 and aim at 15 etc.
When you feel comfortable playing tighter lines you will have better luck at sport shot tournaments.
