Event: Game with promoted variation.
1.e4
1...d5
 |
 +- 1...c5
 |
 +- 1...e5
 |  2.Nf3 Used to be the main line
 |
 +- 1...c6
 |
 +- 1...g6
 |
 +- 1...d6
 |  2.d4 Used to be a nested variation
 |
2.exd5
2...Qxd5 Used to be the variation at index 1
*