Board Thread:Questions and Answers/@comment-6011882-20130411204743/@comment-5706972-20130412031435

Not to make your head explode, but it is all about the: power + 1

Everything else, when you are comparing efficiency, will give you the same result

Example: 700 efficiency

5 x cards with 3500 atk at 5 power (700 efficiency): 25 + 5 / 2 = 15 power used

5 x cards with 7000 atk at 10 power (700 efficiency): 50 + 5 / 2 = 22 power used

3500 * 2 = 7000 using 30 attack power, while

7000 * 1 = 7000 using 22 attack power (and taking half as many hits)

Bottom line: you want the best efficiency in the highest attack card... No kidding, right?