Japanese stadium vs. Original Hasbro

Okay, can't find the topic I found before again. But I found a topic that was gathering up all of Hasbro's new beystadiums and gathering dimensions including slope angles.
I have one of the first beyblade stadiums that hasbro released, it is yellow and has no identification marking of any sort. I just measured the angle on it and found that it had a 15-16 degree angle. Look at those other stadiums this is about 8-10 degrees steeper than the others.

How does this compare with the slope of the Japanese attack stadium?

If this is the wrong place to put this I apologize, but I figured it could stand alone as a thread and didn't fit in the other categories.
I do think it could just belong here :
http://worldbeyblade.org/Thread-Hasbro-B...omparisons

Perhaps get the thread starter to change the title of the topic.