My preferred option is as RPNYC says 3 for a Win, 1 for a Draw and nothing for Losing.
Straightforward and to the point. Dead easy and no reason for anyone to be confused. I think keeping things simple is the way to go, it is a simple Sport. Or it would be if the Rules weren't continually changed to suit one Track/Promoter or another.
Speedway isn't big on credibility sadly.
It is OK - but a little confusing to some.