Dealing with Class Imbalance -- Dummy Classifiers

Let me paint a picture for you, you are a beginner to the field of Data Science and have started making your first ML model for predictions and found the accuracy using model.score() You are jumping around thinking that you nailed it and maybe it was your destiny to become a Data Scientist. Well, I don't want to burst the bubble but you can be horribly wrong. Do you know why? -- Because accuracy is a very poor metric to measure the classifier performance especially in the case of Unbalanced Dataset. And unbalanced datasets are prevalent in a multitude of fields and sectors.