The power bar for me is fairly accurate. If I want to draw tee-line, I wait until the power bar hits the sideline, and then I release. For a tee-line draw, the ideal weight is when the top of the power bar is past the sideline and the bottom of the power bar has not reached the sideline. Therefore, the sideline should be intersecting in the middle of the bar. That's about top 4 weight (though it differs by about 1-2 feet with every throw), then I sweep accordingly. In real curling, the ice is not always the same, so I'm fine with the small imperfections in the ice. It adds a certain level of realism.