Up Down Success is a statistic that shows the number of greenside shots that holed out within two strokes - either by the greenside shot making it in the hole, or by the greenside shot making it onto the green (up) followed by one putt into the hole (down).
Higher numbers indicate better performance; however, a value of 0 can mean that either it took more than two strokes to hole out from a greenside shot indicating poor performance, or that no greenside shots we're taken for that segment.
Up Down Success can be found on the Scrambling Report.