You really don't get it? I said it multiple times, you can not combine a quarter of 1 fiscal year and 3 quarters of anothr and call that a year of shipments. So let me repeat it once again for you, there are 2 possibilities for bets here:
1. We use VGC/NPD/Famitsu/MC for sales data (Sales, NOT shipments).
2. We use Nintendo's shipments for fiscal year 2014.
You choose between the 2.
Yes, you can - you haven't stated why we cannot. Nintendo's quarterly shipments are the only actual numbers that we have worldwide, afterall.
I didn't think i'd have to explain for you (thought you would have known this aready) but here we go. The reason why you can't combine 2 quarters of 2 different fiscal years and call that a *full year* is due to the phenomenon that has already been proved to have happened (Selling more then what they shipped), that phenomenon is called overshipment. Therefor, the 3DS could have sold 15M+ units in 2013. However, since your bet would be using shipment numbers, then, they might have needed to sell their excess of 3DS in Q4 2013 which would falsify the numbers and therefor falsify the result of our bet.
Now I know what your first comeback is going to be "Well, they might have overshipped in Q4 2013 as well which makes you argument invalid?". To answer that concern briefly, usually, Q4 2013 (Or our Q1 2014) mainly consists of selling the remaining of your stock from Q3 2013 (or our Q4 2013) and then some. Meaning, sure, there might be a small disperency, but it won't be anywhere as big as the one between Q3 and Q4. This is why Q4 is mostly all the time one of the slowest selling periods for Nintendo or any other company. EDIT: (In terms of shipments).
Since we are both looking to do a fair bet, we want to use the most accurate data to know who the winner is. Which, since you seem so reluctant to use the sell through data that we have, then the most accurate data to use would be the full FY 2014 of Nintendo.