6 tie off holes, of which 4 will be used. A typical One peice only has 4 tie off holes. With the exception of Prince O-Port rackets, where you can only string it one way by design.
How do to know what a tie off hole looks like? If you can essily put two pieces of string, with little or no effort, in a grommet that's probably a tie off hole. Though some Wilson rackets have very large grommet holes.