What is the advantage of having four chambered heart?

The four-chambered heart is found in all mammals, birds and in the crocodile. In four chambered heart, left half is completely separated from right half by septa. Thus, It prevents the mixing of oxygenated and deoxygenated blood.

Second, it allows the efficient supply of oxygenated blood to all parts of the body. This is useful in animals that have high energy needs such as mammals and birds.