To do a 50-50 roll up in the ollie position. Have the object in front of you and roll in the same direction it goes except roll a little at an angle towards it so when you olle you can get on it. Ollie and land with both trucks on the rails keep your balance. When you get to the end ollie or push down on the tail to get out. To get off before the end push down on the tail and turn off. When you land keep your weight centered and roll away smooth.