Originally Posted by 
The Boz
                     
                Why not do the math on betting each straight, then as the parley, then how you make out if both win or if you split. 
Then you have the answer. And the answer may not be if you had an advantage, but did you give some advantage away. Or did you gain some compared to betting them individually? 
And how can you quantify “85%” chance? Historical numbers or just estimated?
It’s an interesting question you asked.