By the use of decomposition for the three-dimensional flow field in compressors into independent through flow and cross flow as first proposed by Chen et al., the tip gap flow structure for different tip gap heights and boundary conditions is examined. Tracing the roll up of a shear layer in planes normal to the blade camber line the position of the tip leakage vortex is presented in a non-dimensional formulation. Tests for different boundary conditions, i.e. the distinction between a stationary and a rotating end-wall as well as the use of different fluid models are made to quantify their influence on the tip leakage vortex position. By comparing the analytical result to data extracted from three-dimensional RANS computations and to measurement data the validity of the model is presented. Finally, an attempt is made to find a criterion for the occurrence of tip leakage vortex induced stall of tip critical rotor blades. This is done by a correlation based on the previously derived non-dimensional vortex trajectory and the stagger angle. This criterion is again tested on results of a three dimensional RANS computation proving its validity.