If two geodesic particles collide near a rotating black hole, their energy in the centre of mass frame Ec.m.can become unbound under certain conditions (the so-called Mens athletic-sweaters BSW effect).
The special role is played here by so-called critical geodesics when one of particles has fine-tuned energy and angular momentum.The nature of geodesics reveals itself also in fate of the debris after collisions.One of particles moving to a remote observer is necessarily near-critical.
We discuss, when such a collision can Horse Bridles give rise not only unboud Ec.m.but also unbound Killing energy E (so-called super-Penrose process).