Hedron alignment | Art by Craig J. Spearling
Looking at a Different Angle
Typically, to prepare for a new set, it's good to put time into understanding the new cards. The most obvious way is to look through the cards almost like flash cards to understand it. Other ways are to read articles, look at new mechanics, understand limited archtypes, read card set reviews, and just starting to play with the cards. However, sometimes there are completely different ways to check out and learn about the set as well.
Diego Fumagalli over at Visualizing Magic has poured over a lot of data that is available for the new set and has put it together in a way to understand it all. I recommend using it as a tool to understand the format in general and see potential impact of Oath of the Gatewatch going forward.
Take a look below.
Hope this can be a helpful tool and be eye opening.