Open Game: Inverted Philidor

Open Game

Definition

An Open Game is any chess opening that starts with the moves 1. e4 e5. Because both sides immediately contest the centre with a pawn and leave no pawn directly blocking the e-file, the resulting positions tend to feature open lines, rapid piece development and tactical possibilities. You will sometimes see the synonym “Double King’s-Pawn Game” in older texts.

Usage in Opening Classification

Modern opening manuals and databases (ECO codes C20–C99) group every branch beginning 1. e4 e5 under the umbrella of the Open Game, before breaking the family into well-known sub-openings:

• C50–C59: Italian Game (Giuoco Piano, Evans Gambit, etc.)
• C60–C99: Ruy López (Spanish), including the Berlin, Marshall, and other defences
• C44–C45: Scotch Game and Gambit lines
• C33–C34: King’s Gambit
• C41: Philidor Defence and off-shoots such as the Inverted Philidor (see next section)
• C42–C43: Petrov Defence (Russian Game)

Strategic Significance

Because central tension is resolved early (pawns often exchange on d4 or f5), Open Games usually lead to:

• Open or semi-open files for rooks and queens.
• Freer development for both bishops, especially the c1- and f1-bishops.
• An emphasis on tactical motifs such as pins on the e-file, discovered attacks after pawn exchanges, and early king-side assaults.

Historically, the Open Game dominated top-level play through the 19th century. Even today, elite grandmasters return to the main Ruy López or Italian Game when they need a fighting game with classical foundations—witness Carlsen–Karjakin, World Championship 2016.

Illustrative Example

The famous “Immortal Game” (Anderssen vs. Kieseritzky, London 1851) begins 1. e4 e5 2. f4 exf4— the King’s Gambit Accepted, an archetypal Open Game where open lines allow a cascade of sacrifices culminating in mate.

Interesting Facts

• Before the wide adoption of positional openings like the Queen’s Gambit, every recorded world-title game (Steinitz–Zukertort 1886) started with an Open Game.
• Computer engines still evaluate the initial 1. e4 e5 position as almost perfectly balanced (+0.2 to +0.3 for White), illustrating its theoretical soundness.
• Open-Game specialists such as Paul Morphy and José Raúl Capablanca were famed for their effortless piece co-ordination—skills that the transparency of 1. e4 e5 positions accentuates.

Inverted Philidor

Definition

The Inverted Philidor is a sub-variation of the Open Game in which White adopts the structure normally associated with Black’s Philidor Defence, but does so with an extra tempo. The most common move-order is:

1. e4 e5
2. Nf3 d6
3. d4! exd4
4. Nxd4 …

After 3. d4, White has traded the classical Philidor’s cramped reputation for central space and rapid development, while Black must decide whether to transpose into a Philidor Exchange (4…Nf6) or seek independent paths. Because the colours of the Philidor set-up are literally reversed—hence “inverted”—the variation is also catalogued in databases as C41: Open Game, Inverted Philidor.

Typical Plans and Ideas

• White enjoys a lead in development and open central lines after the early pawn exchange. Common follow-ups include 5. Nc3, 5. Bb5+ or 5. Bc4, targeting f7 and exploiting Black’s slight lag.
• Black chooses between solid but passive defences (…Be7, …Nf6, …0-0) or more adventurous setups (…g6 and a King’s-Indian-style fianchetto).
• The structure resembles an Open Philidor but the extra tempo gives White sufficient pressure to fight for a tangible edge rather than merely equalising.

Historical Context

The name appears in 19th-century manuals; James Mason and later Aron Nimzowitsch recommended the line as a straightforward antidote to 2…d6 players who hoped to avoid theory. Although never the fashionable main line, it remains a practical choice at club level because:

• White sidesteps the heavily analysed Ruy López while still confronting Black in the centre.
• Black Philidor specialists may feel uncomfortable playing the same structure but a tempo down.

Model Game

Carlsen – Vachier-Lagrave (Blitz, Paris 2017). Even in fast time-controls White reached a pleasant, risk-free position, illustrating the line’s practical value.

Interesting Nuggets

• Because White’s early 3. d4 resembles the Scotch Game, some authors dub the Inverted Philidor a “Scotch-Philidor hybrid.”
• Engines rate the starting position after 4. Nxd4 at roughly +0.40—slightly better than the theoretical +0.25 of a main-line Philidor with colours reversed.
• Grandmaster Nigel Short popularised the alternative move-order 1. e4 e5 2. d3, calling it “the Philidor with a free move.” Though formally a separate opening (King’s Pawn, C20), it often transposes to the same structures.