The TD learning algorithm was introduced by Richard S. Sutton in 1988. In the introduction of the chapter, we learned that the reason the TD method became popular is that it combines the advantages of DP and the MC method. But what are those advantages?
First, let's recap quickly the advantages and disadvantages of DP and the MC method.
Dynamic programming—The advantage of the DP method is that it uses the Bellman equation to compute the value of a state. That is, we have learned that according to the Bellman equation, the value of a state can be obtained as the sum of the immediate reward and the discounted value of the next state. This is called bootstrapping. That is, to compute the value of a state, we don't have to wait till the end of the episode, instead, using the Bellman equation, we can estimate the value of a state just based on the value of the next state, and this is called bootstrapping.
Remember how we estimated the...