black line which is running closer to horizontal compared to the red line now one thing you also want to do and don't want to forget about is cross-validation so whenever you have some data and you just fit to the data it's possible that you're memorizing data over fitting it rather than paying attention to the real pattern we saw this in valuation sample based valuation you don't want to just over fit the few samples and make sure that you fit your neural net in a way that it generalizes to other data so people we do is you split your data into