In this week's lesson, Dennis begins his coverage of the Marshall with an analysis of key sidelines. He covers one last anti-Marshall (9.d4) and then moves on to a few weaker (but tricky!) lines for black, 9.exd5 e4?!, Marshall's original 9...Nxd5 10.Nxe5 Nxe5 11.Rxe5 Nf6, and 11...Bb7. Stay tuned for coverage of the Marshall's main lines!