Can you say the main difference between an arranged marriage and love marriage?
both has failures if there is misunderstanding and both has success if there is understanding.that is if there is love between each other to give up and manage negative aspects of each other then they become successful partners in marriage.

If all the love marriages made with proper love and not lust then there shouldnot be failures in love.

So one should select a partner only after knowing his basic negative aspects in character and check whether that can be managed emotionally or not before confirming love.

to check it, one should talk different critical life situations faced by variuos people in dayto day life to the partner and ask his reaction and how he will react in such situation.
This shall give an idea about his/her basic character make up.

love requires plan using brain but love becomes blind as it uses emotion that is heart.this is the main problem for your confusion.