[QUESTION] Chapter 2 - Using GridSearch result

I'm tripping up on a few things at the end of chapter 2... at the moment I'm trying to get my head around the GridSearch result.

Referring to the Jupyter notebook...

Line 94
`forest_reg = RandomForestRegressor(n_estimators=100, random_state=42)`
n_estimators = 100 which gives a result of 50,182.

Later in the text we use Grid Search to automatically change hyperparameters.
Line 99
`{'n_estimators': [3, 10, 30], 'max_features': [2, 4, 6, 8]},`
The best result is 49,682 (max_features: 8, n_estimators: 30)

If you change n_estimators on line 94 to 30 you get 50,696. It makes sense to me that its bigger than the default in line 94 but why is the result from Grid Search smaller?

I've tried changing line 99 to
`{'n_estimators': [30, 100], 'max_features': [8]},`
and this gives the results
49682.273345071546 {'max_features': 8, 'n_estimators': 30}
49219.71678391268 {'max_features': 8, 'n_estimators': 100}

My question is, what do you do with the result of the Grid Search? Why doesn't n_estimators give the same result both times? How does max_features fit in with regard to line 94?

Thank you!