start

A flying start is fast; a head start is early.

Which is against the rule?

contrapositionWhich is against the rule?

A head start...unless a handicap is offered.

contrapositionWhich is against the rule?

In athletics (sprinting), a "flying start" is usually a start that is almost illegal -- one that seems to anticipate the gun, but not quite by enough to be deemed illegal. It is possible that some people might sometimes use the term to mean a true false start (illegal start).

GPYnot quite by enough

What doe you mean by 'by'?

contrapositionWhat doe you mean by 'by'?

You anticipate the gun by a certain amount of time (tenths or hundredths of a second, probably). In my sentence, the amount of time is "enough ( time ) to be deemed illegal".