Basically the idea of sprints is to clear a specific # of lines as fast as possible;

Snewsnew: for my idea for everyone doing sprints is to focus more on building center-well tetris builds

Mod edit: Centre wells are a good strategy to have some of the least spins and movements for blocks, there is also a still viable right well as the spins for each block favour that side, as does the tspin triples favouring the left more. One factor is gonna be really important : Finesse. The less finesse you have, the faster you will be. Most top players have 0 finesse. So reducing your finesse means doing the less spins, movements, soft drops, and to das when possible.