see attached photo. Track pitch is the measurement between A & B or C & D. These measurements should be the same on each side. If a worn track link was replaced on one side and not the other, the track measurement (or pitch) would be different from one side to the other. If this happens, the drive rollers (figure E) may not drop to the bottom of each sprocket tooth. If the measurements between F & G are not the same as the measurements between H & I, bend the links on the long side to make them the same as the short side. If one side is longer than the other, the track will not run straight and will wear the roller flanges or derail the track. After this adjustment use a half link if necessary and then adjust your end adjusters for proper track tension