After an extensive literature search I found that its semi major axis a is 1.4245 ten power 14 metres, its eccentricity eps is 0.8831 plus or minus 0.0034 and it orbits a central mass M of 7.956 ten power 36 kilograms. So in the Einstein theory the precession can be worked out from delta phi = 6 pi MG / (a(1 – eps squared) c squared)) per orbit of the star around a mass M situated near Sagittarius B. This is a good candidate for the application of ECE2 relativity. I looked at many sites and found a Max Planck institute site that gave the semi major axis in light days. I have reduced reduced all data to S. I. units. The literature does not mention strong gravitation in this case. The measured perihelion advance is about 2 degrees a year according to one site but we shall see what a careful calculation comes up with. The orbit is an ellipse with a large precession per orbit. I am proceeding to a new phase of criticism of the Einstein theory, criticism of strong field gravitation. The standard model has already been sieved by Stephen Crothers, who has shown that strong field gravitation is riddled with errors and has catalysed howls of rage. One of them got into the newspapers.The strong field theory is completely wrong because it neglects torsion. CEFE sieves black hole theory and all known metrics of the Einstein field equation. They still claim pristine precision.