THE "ÉPINE DORSALE" (or DORSAL FIN)

The chess term for a short sequence of established initial moves forming the gateway to the many "Kings Pawn" openings and variations (which form the majority of games). See Animation.

White 1.P-K4 Opening
1..Black def. 2. White 2..Black def. 3. White 3..Black def.
1..P-K4 (=épine) 2.Kt-KB3 (épine) 2..Kt-QB3 (épine) 3.B-QB4 (épine)
or
..P-QR3 St.George
..P-QKt3 Q.Fian.
..Kt-QB3 Nimzo.
..P-QB4 Sicilian
..P-QB3 Caro-Kann
..P-Q4 Cent-Countr
..P-Q3 Pirc
..P-K3 French
..P-KB3 Barnes
..P-KKt3 Modern
..Kt-KB3 Alekh.
 or
2.P-QB3 Centre Pn.O.
2.Kt-QB3 Vienna
2.P-Q4 Centre Game
2.P-Q3 Indian O.
2.P-KB4 K-Gambit
2.P-KB3 K-Head
2.B-QB4 Bishop's
2.Kt-K2 Alapin/Hippo
 or
..P-Q3 Philidor's
..P-Q4 QP-CtrG
..Q-B3 Greco
..P-KB4 Latvian
..P-KB3 Damiano
..Kt-KB3 Petroff
 or
3.B-Kt5 R.Lopez
3.Kt-QB3 4 Kts
3.P-QB3 Ponziani
3.P-Q4 Scotch
3.B-K2 Tayler O.
3.KtxP (to) Chicago G.
 then
..B-QB4 Giuoco
..P-Q3 Paris
..B-K2 Hungar'n
..Kt-KB3 2 Kts
..P-KB4 Rous.G.
..Kt-Q5 Shilling
Development Principles or Categories of Opening or Clear or Groups