9 is a smart score to give
He can't give it a 10, because that would come across as cocky and people would then expect perfection.
He can't give it an 8, because while 8 is a good score, it's not a great score and he should be striving for greatness.
He can't give it 7 or lower, because that flat out doesn't look good
So he gives it a 9, because that shows he feels he made a great game, but isn't trying to hype it up too much and is being humble.







