1. A computer-implemented method for predicting a user navigation event, the method comprising: rendering a web page in a web browser; identifying a user navigation event within the web browser; in response to the user navigation event, storing an address of the web page and a destination address associated with the user navigation event in a data structure, the data structure comprising a map indexed by one or more source addresses, the one or more source addresses being mapped to one or more destination addresses, each destination address being associated with a frequency value indicating a number of visits to the destination address from an associated source address of the one or more source addresses; determining, using a processor, a probability value representing a likelihood of selection of each destination address from each source address, wherein the probability value is determined by dividing the frequency of a particular destination URL from a particular source URL by the frequency of all navigation events from the particular source URL; and using the probability value for each likelihood to predict a next navigation event.