Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...Qf6

Frankfurt defence
a
b
c
d
e
f
g
h
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
a
b
c
d
e
f
g
h

Position in Forsyth-Edwards Notation (FEN)
Moves: 1. e4 e5 2. Nf3 Nc6 3. Bb5 Qf6
ECO code: C60—99
Parent: Ruy Lopez

3...Qf6!? · Frankfurt defence

edit

The move 3...Qf6!? is a rare and provocative sideline in the Ruy López. Ignoring conventional wisdom, Black develops their queen early.

3...Qf6 aids in the defense of the e5 pawn as well as the knight on c6. Further, the queen adds a piece to the control of d4 and looks to potentially start a future kingside attack. If White delays castling, the queen can route to g6 (typically in response to Nc3 to Nd5) and pressure the undefended g2 pawn.

Black's plan typically includes developing with Bc5 and Nge7, often delaying the advancement of the d-pawn. Black may also opt to play Bd6 instead staying solid and with an eye on h2 should the diagonal open up. While the king knight is denied its usual post on f6, from e7 it can control d5, preventing White from easily playing Nd5 and also nullifies White's threat of trading off the knight on c6 and damaging Black's pawn structure.

White's plans are, as usual in the Ruy López, to castle quickly and take over the center with c3 and d4 pawn pushes.

4. c3 readies a d4 advance. Black can respond with Nge7, Bd6, Bc5, or a6. g5 is particularly provocative, aiming to advance to g4 and displace White's knight.[1]

4. O-O may be met by 4...Bc5 5. c3 Nge7. On e7, the knight is ready to capture back if Bxc6 and therefore keep control of the center.

4. Nc3 develops a piece usually with an aim to play Nd5, displacing the black queen and potentially hindering Black's development and/or defense of e5 and c7.

Themes

edit

The Frankfurt Defence is quite sharp and often requires careful positional play that can take on many different characteristics. Sometimes this involves open lines after trading some minor-pieces and other times Black will try to keep things closed with careful positioning of pieces. While White can force the position open with an exchange of pieces, this can liberate Black's remaining pieces, freeing them for counterplay.

With 4. Nc3, White may attempt to dominate early, aiming to plant a knight Nd5 to harass the Black queen. This leaves the e4 pawn undefended. As in many Ruy López positions, if White is not mindful of this pawn when they are uncastled, the Black queen can exploit this vulnerability.

4...Bd6 is a thematic move, where Bc5 is impractical because of the c7 vulnerability. Despite looking anti-positional, the bishop holds both the e5 and c7 pawns and can potentially become useful in an assault on h2 in the future. Black's light-square bishop will often be content to sit on it's starting square, aiding in king-side play after the d-pawn has moved. Alternatively, it sometimes finds a home on b7 after using the a and b pawns to kick White's light-square bishop away. a6 in particular works well in conjunction in positions where Bc5 is played instead of Bd6, giving Black's dark-square bishop a retreat square, potentially allowing both of Black's bishops to eye White's kingside from relative safety.

After 4. Nc3 Bd6 5. Nd5 Qg6 (see Diagram 1), Black's queen is threatening to win the pawn on e4. Play typically continues with 6. O-O or 6. d3 securing the e4 pawn. Instead, if White is careless and plays 6. Nh4 then 6...Qxe4+ wins a piece.

Instead of committing to Nd5, White may opt to castle. This gives Black the opportunity for 5...Nd4 6. Nxd4 exd4 7. Nd5 Qh6 (see Diagram 2). This blows up the center where we can see the thematic bishop on d6 come good in a mating threat that can potentially weaken White's queen-side. In exchange, White has much better development and can quickly mount an attack on the e-file, often forcing the Black king to see safety on d8.

Another theme that arises from time to time is a c6 fork of the bishop on b5 and the knight on d5 after Black's knight has vacated c6. This can arise in a line such as 5. d4 Nxd4 6. Nxd4 exd4 7. Nd5 Qg6 8. O-O c6 (see Diagram 3). While Black is certainly worse in this particular line, the idea presents itself in similar configurations and is incumbent on White to play accurately.

a
b
c
d
e
f
g
h
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
a
b
c
d
e
f
g
h
Diagram 1
a
b
c
d
e
f
g
h
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
a
b
c
d
e
f
g
h
Diagram 2
a
b
c
d
e
f
g
h
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
a
b
c
d
e
f
g
h
Diagram 3

History

edit

3...Qf6 has no official name in the Encyclopedia of Chess Openings (ECO). The book The Ruy Lopez: Winning Chess with 1 P-K4 (1963) by Leonard Barden predates the ECO and calls this variation the "Frankfurt Defence".[2] They place it towards the "outrageous" end of their list of "irregular and bizarre defences".

While the origins of the name are uncertain, the "Frankfurt Defence" is possibly attributed to a 3...Qf6 game between Jean Taubenhaus and Louis Paulsen during the 5th DSB Congress, in Frankfurt, Germany in 1887.[3]

Documented theory for 3...Qf6 dates back to at least 1843 in the Handbuch des Schachspiels (Handbook of Chess). It cites the dubious line: 4. c3 a6 5. Bxc6 Qxc6 6. O-O Qxe4 7. Nxe5 Be7 8. Re1 Qf5 9. d4 d6 10. Nf3 Be6. The Handbuch notes that white is likely better off with 4. Nc3 instead.[4]

One of the earliest recorded games of 3...Qf6 was played in Howard Staunton vs Bernhard Horwitz at the then London Chess Club in 1846.[5]

In 2021, Grandmaster Aman Hambleton experimented with this opening and, finding there was no official name for it in the ECO, gave it the eponym "The Hambleton Defense" and noted its tricky king-side play.[6]

The Chess.com opening book refers to the opening as the "Ruy López Opening: Gunderam Variation" apparently by analogy with the Gunderam defence, 1. e4 e5 2. Nf3 Qe7. In the Gunderam defence, Black also defends the e5 pawn with the queen, but this involves an early Qe7 not Qf6 and Gerhart Gunderam is not known to have had an affiliation with 3...Qf6.

Theory table

edit

For explanation of theory tables, see theory table and for notation, see algebraic notation.

1. e4 e5 2. Nf3 Nc6 3. Bb5 Qf6

4 5 6 7 8 9 10
Frankfurt defence Nc3
Nge7
d3
Nd4
Nxd4
exd4
Ne2
c6
Ba4
d5
O-O
g6
b4 [2]
c3
g5
d4
g4
Nxe5
Nxe5
dxe5
Qxe5
O-O
Bc5
c3
Nge7
Re1
a6
d4
axb5
dxc5
O-O

When contributing to this Wikibook, please follow the Conventions for organization.

References

edit
  1. e.g. Micheli v Mariotti, 1969 - Chessgames.com
  2. a b Barden, Leonard (1963). The Ruy Lopez: Winning Chess with 1 P-K4. Oxford: Pergamon Press. pp. 153–4. ISBN 0 08 009997 1.
  3. "Jean Taubenhaus vs Louis Paulsen (1887)". www.chessgames.com. Retrieved 2025-06-28.
  4. Baron von Heydebrand und der Lasa, Tassilo (1843). Handbuch des Schachspiels (in German). Germany: Veit. p. 168.
  5. "Howard Staunton vs Bernhard Horwitz (1846)". www.chessgames.com. Retrieved 2025-06-28.
  6. Hambleton, Aman (Chessbrah) (2021-11-17). "I invented a NEW chess opening". Youtube. Retrieved 2025-06-18.

See also

edit



v · t · e
Chess openings quick reference
1. e4
2. Nf3
With 2...Nc6:
Four knights: ()
Italian game: ()
Spanish game: ()

With other 2nd moves:
2. Other
1... other
1. d4
Flank
Unorthodox