Dr. Alexey Root showed the first five moves of a game featuring the London System (chess opening) to Denton High School chess club students. The moves were 1. d4 d5 2. Bf4 Nf6 3. e3 c5 4. c3 Nc6 5. Nd2 Qb6. The game was V. Sergeev vs. L. Cernousek, Jirasek Memorial, Rakovnik 2008 featured on pages 49-53 of Cyrus Lakdawala's Play the London System (Everyman Chess, 2010).
Then pairs of students continued with move 6 and notated through move 20. Then Dr. Root analyzed the games with each pair after each pair's 20th move. Because most students played slowly, only one pair had time to try the opening again (another 20 moves, with switched colors), to see which side they liked playing more.