It seems irrational to take or dispense credit or blame for matters over which a person has no control, or for their influence on results over which he has partial control.

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If someone has had too much to drink and his car swerves on to the sidewalk, he can count himself morally lucky if there are no pedestrians in its path. If there were, he would be to blame for their deaths, and would probably be prosecuted for manslaughter. But if he hurts no one, although his recklessness is exactly the same, he is guilty of a far less serious legal offence and will certainly reproach himself and be reproached by others much less severely. To take another legal example, the penalty for attempted murder is less than that for successful murder - however similar the intentions and motives of the assailant may be in the two cases. His degree of culpability can depend, it would seem, on whether the victim happened to be wearing a  bullet-proof vest, or whether a bird flew into the path of the bullet - matters beyond his control.