Playtesting: the importance of getting to the end:

“And there’s also value in observing that, unless you push through with a playtest, and begin to interrogate the further reaches of your game, you won’t know how early decisions can impact the game later on. This, dear reader, is what people call strategy.”

http://www.brettspiel.co.uk/2013/04/playtesting-importance-of-getting-to-end.html