This is an example of a duplicate bet:
Barcelona v Real Madrid - Match Odds, Barcelona @2
Barcelona v Real Madrid - Match Odds, Barcelona @3
Below is duplicat bet or not :
Case 1 :
ManUtd v Malmo - Total goal, 3 goal or more @2
ManUtd v Malmo - Total goal, 2 goal or more @1.3
Case 2 :
ManUtd v Malmo - Total goal, 3 goal or more @2
ManUtd v Malmo - Over/Under, over 2,5 goal @2.2
Case 3 :
ManUtd v Malmo - Total goal, 3 goal or more @2
ManUtd v Malmo - Match Odds, Malmo @4.5
Cases 1 and 3 are not duplicate bets. We are currently analizing case 2 and will let you know.
Case 2 should be a duplicate bet because more than 2.5 is 3 or more. (AFAIK goals can't be fractions

) so it would be betting on exactly the same thing at different odds.
Kind of like:
Case 2 :
ManUtd v Malmo - ManUtd wins.
ManUtd v Malmo - Malmo loses & not a draw.