Chances to make an unusual point (4)
I believe the answer is:
odds
'chances' is the definition.
(I've seen this before)
'an unusual point' is the wordplay.
'an unusual' becomes 'odd' (I've seen this before).
'point' becomes 'S' (S is an example).
'odd'+'s'='ODDS'
'to make' is the link.
(Other definitions for odds that I've seen before include "familiar to our betters?" , "Measure of probability" , "Likelihood of something happening" , "Betting figures" , "Chances of occurrence" .)