When and Why Statisitcal Learning Works

This video explains briefly how Google machine translation works (by using statistical learning). It says

A computer can learn foreign language … by referring to vocabulary and a set of rules. But … When you try to capture all of these exceptions, and exceptions to the exceptions, in a computer program, the translation quality begins to break down.

This explains when and why statistical learning might be helpful, compared to human summarized rules, from the perspective of machine translation.