Ramified core of historical games (simplified version)

My previous thread

https://www.chess.com/forum/view/chess-openings/ramified-core-of-historical-openings

looks too complicated. Here, I give a simpler version not going too far into opening ramifications. I'm starting with first 25 games in chessgames.com database.

• 2E --> 2Ed Scandinavian defense, Castellvi - Vinyoles (1475), 1.e4 d5
• 2E --> 2Ee --> 6e2E --> 6Ee --> 6Ee1d Petrov defense: Damiano variation: Kholmov gambit, Damiano - NN (1497), 1.e4 e5 2. Nf3 Nf6 3. Nxe5 Nxe4 4. Qe2 Qe4 5. Qxe4 d6
• 1E Van't Kruijs opening , NN - Lucena (1497), 1. e3
• 2E --> 2Ee --> 2Ee1f --> 6e2E1f --> 6f2Ee Damiano gambit, Damiano - NN (1512), Ruy Lopez - Da Cutri (1560), 1.e4 e5 2. Nf3 f6 3. Nxe5 fxe5 4. Qh5
• 1C Saragossa opening , Lucena -Quintana (1515), 1. c3
• 2E --> 2Ee --> 2Ee1C --> 2DEe1C Giuoco Piano: Main Line, Scovara - Boi (1575), Castiglio - Polerio (1575), 1. e4 e5 2. Bc4 Bc5 3. Nf3 Nc6 4.  c3 Qe7 5. d4
  
• 2E --> 2Ee --> 2Ee1C --> 2BEe1C Giuoco Piano: Main Line, Da Cutri - Ruy Lopez (1575), 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. c3 Qe7 5. b4
• 2E --> 2Ee --> 2Ee1d Philidor defense, Da Cutri - Ruy Lopez (1575), 1. e4 e5 2. Nf3 d6
• 2E --> 2Ee --> 2Ee1C --> 2Ee1Cd --> 2DEe1Cd Giuoco Piano: Main Line, Polerio - Lorenzo (1575), Saduleto - Polerio (1575), Busnardo - NN (1575), Saduleto -Polerio (1590), Busnardo -NN (1590), 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. c3 Qe7 5. O-O d6
• 2E --> 2Ee --> 2EFe --> 2EFe1d King's gambit, Ruy Lopez - Da Cutri (1575), 1. e4 e5 2. f4 d6
• 2E --> 2Ee --> 6E2e --> 6Ee --> 6Ee2d Petrov defense: Boden-Kieseritzky gambit, Da Cutri - Perbin (1580), 1.e4 e5 2. Nf3 Nf6 3. Bc4 Nxe4 4. Nc3 Nf6 5. Nxe5 d5
• 2E --> 2Ee Greco defense, Greco - NN (1590), 1.e4 e5 2. Nf3 Qf6
• 2E --> 2Ee --> 2Eef Latvian gambit: Mayet attack, NN - Greco (1590), 1.e4 e5 2. Nf3 f5 3. Bc4
• 2E --> 2Ee --> 6e2Ef Latvian gambit accepted, Polerio - Da Cutri (1590), 1.e4 e5 2. Nf3 f5 3. Nxe5
• 2E --> 2Ee --> 2EFe --> 6F3f2E0f King's gambit accepted: King's Knight gambit, Benavides - Saduleto (1590), 1. e4 e5 2. f4 exf4 3. Nf3
• 2E --> 2Ee --> 2EFe --> 6F3f2E0f King's gambit accepted: Bishop's gambit, Polerio - Busnardo (1590), 1. e4 e5 2. f4 exf4 3. Bc4
• 2E --> 2Ee Italian game: Two Knights defense, Polerio -Domenico (1610), 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 
• 2E --> 2E1b Owen defense , Greco - NN (1619), 1. e4 b6
  
• 2E Bishop's opening : Boi variation: Lopez variation, Greco - NN (1620), 1. e4 e5 2. Bc4 Bc5 3. Qe2
  

sorry but i dont understand..

Hey Billy, sorry, I note pawn structure codes in bold. So, I wanna classify chess openings not by moves but by pawn structrures.

ok