I calculated OJ287 binary black hole system with Swarzshild General Relativity system and I got two different perihelion shift values (not rounded numbers): 27.73298398 degrees and 27.79877741 degrees per one orbit. I got two analytic solutions also but above was calculated with primary solution. Ref. Lankeswar Dey et al. 2018. The Astrophysical Journal. 866:11 (20pp), 2018 October 20. Table 2/page 7. Best Regards, Hannu Poropudas, Finland.