The initial act of launching a sailplane at most thermal duration contests in USA may ultimately be the success or failure of your chance of achieving a good score. As DP says launch height is king. Especially when the task is F3B speed or distance where there is rarely time in the task to circle and gain altitude. For thermal duration tasks when the air is soft or there is no thermal activity at all like early morning rounds it is imperative to obtain the greatest height possible in order to maximise the time in the air. Even when good conditions are available, height remains the single starting variable that you have control over. If you launch higher than your average competitors you will be able to scout further for lift and stand a much better chance of finding good air. In the long run you will see what the effect is when you consistently out float your rivals. Below is an excellent series of articles written by experienced RC soaring pilots on how to extract the best from your launch setup.