Also called Petroff's Defence or the Russian Game. Though this symmetrical response has a long history, it was first popularized by Alexander Petrov — a Russianchess player of the mid-19th century. The Petrov has a reputation of being dull and uninspired. However, it offers attacking opportunities for both sides, and a few lines are quite sharp. Often a trade occurs, and Black after gaining a tempo gains a well placed knight.