Before start of race, punter is richer (6,3)
I believe the answer is:
better off
'richer' is the definition.
(I've seen this before)
'before start of race punter' is the wordplay.
'before' is a charade indicator (letters next to each other).
'start of race' becomes 'off'.
'punter' becomes 'better' ('better' can be a synonym of 'punter').
'off' after 'better' is 'BETTER-OFF'.
'is' is the link.
(Other definitions for better off that I've seen before include "with more money" , "Richer" , "having lost less" , "wealthy" , "Someone setting out for the bookies" .)