Energy is usually being split according to the conductance of the available paths, not taking those into account which have a higher loss than the total amount of eu emitted from the energy source. Paths leading to targets which currently don't accept energy (usually because their internal buffer is full) will be ignored as well.
The previous calculation yields the minimum amount of eu sent to the various destinations, however there are some targets which don't get their full share because they are either almost filled up and the energy gets partially rejected or the share is not larger than the path loss. Those lost shares are being collected and sent in further distribution rounds, just like the original method, but with randomly eliminating targets in stalemate situations. This situation occurs when all shares were unable to be distributed as in everyone would get less than 1 eu = effectively 0. Reducing targets increases the share of the others, ultimately to one which gets everything or even zero if the last possible path is too lossy.