6. A hybrid prediction computer system for processing training data to predict click-through-rates, said hybrid prediction computer system processing training data by: creating a machine learning based model for making a base prediction, said machine learning model constructed using a first set of features in training data; creating a tree-structured statistical table from a second set of features in training data by applying Kalman-filter methods to a tree-structured Markov model to estimate parameters in said tree-structured statistical table; executing said machine learning model using said first set of features from test data; and adding an adjustment factor from said tree-structured statistical table to augment said base prediction from said machine learning based model to predict click-through-rates.
6. A hybrid prediction computer system for processing training data to predict click-through-rates, said hybrid prediction computer system processing training data by: creating a machine learning based model for making a base prediction, said machine learning model constructed using a first set of features in training data; creating a tree-structured statistical table from a second set of features in training data by applying Kalman-filter methods to a tree-structured Markov model to estimate parameters in said tree-structured statistical table; executing said machine learning model using said first set of features from test data; and adding an adjustment factor from said tree-structured statistical table to augment said base prediction from said machine learning based model to predict click-through-rates. 7. The hybrid prediction computer system as set forth in claim 6 wherein said machine learning based model considers a limited important set of global features.