GripUse a ball with a conventional grip, placing your fingers in the ball up to the second knuckle. The Basics of Grip and Ball website notes that this grip gives the best feeling of control and security. The two middle fingers go in the finger holes. The index and small fingers span out as wide as possible. Your second hand can cup over the bowling hand or hold the side of ball for stability in your starting position.
SwingYour swing of the ball, your approach to the foul line and your release of the ball are all interconnected. You must perfect the timing of these components to deliver an accurate straight ball to the lane consistently. Complete Bowling Index emphasizes not to accelerate to decelerate the swing, but rather allow gravity to move the ball through the swing. This will create the greatest consistency of delivery.
Ball ReleaseYour actual release of the ball at the foul line has the greatest impact on what the shot will look like on the lane. The angle at which your fingers leave the ball defines the shot. To bowl straight, both fingers must leave the holes at the same time and come out the back of the ball, rather than the side like for a hook shot.
Ball TypeThe shape of the weight inside the ball will determine how it reacts on the lane and to the lane conditions -- oily or dry. To have a ball that runs straight, you need to have a ball drilled central to the weight axle within the ball. A good release of the ball will then deliver it to the lane balanced on the axle. Experienced bowlers will often purposely have the ball drilled off center from the weight to create hook on the lane.