Another, more significant and quite popular sideline occurs for Black on move 6, with 6...Bg4, in place of the mainline 6...e5. One idea for Black here is to relieve their somewhat cramped position by exchanging their light-squared bishop, which is often relegated to a passive role in the King's Indian. White's most popular response is 7.Be3, similar to the Gligoric System (see above); White seems to retain a small edge in every variation. Top players who have used this line for Black include two former World Champions: GMs Mikhail Tal and Boris Spassky.