D90 Grünfeld Defense: Three Knights Variation
D90 holds three named lines, all under the name Grünfeld Defense. It leaves D80 (Grünfeld Defense) with 4.Nf3. Lines of nine other codes continue from its position, the second-widest spread of the 20 Grünfeld Defense codes. Lines filed under D85 reach one of its named positions by a different move order.
| # | White | Black |
|---|---|---|
| 1 | d4 | Nf6 |
| 2 | c4 | g6 |
| 3 | Nc3 | d5 |
| 4 | Nf3 |
The move that completes D90
The reference line of D91 plays all of these moves and continues beyond them; D90 is the position reached at 4.Nf3.
- 4.Nf3 The knight leaves g1 for f3, opening a line for the rook on h1.
Lines filed under D90
All three share their first seven plies, the whole reference line.
| Name | After the shared start | Plies | At the end |
|---|---|---|---|
| Grünfeld Defense: Three Knights Variation | (the shared start itself) | 7 | |
| Grünfeld Defense: Three Knights Variation | 4...Bg7 | 8 | |
| Grünfeld Defense: Flohr Variation | 4...Bg7 5.Qa4+ | 9 | check |
Grünfeld Defense: Three Knights Variation
- 4...Bg7 The bishop leaves f8 for g7, opening a line for the rook on h8, guarding the rook on h8.
Grünfeld Defense: Flohr Variation
- 4...Bg7 The bishop leaves f8 for g7, opening a line for the rook on h8, guarding the rook on h8.
- 5.Qa4+ The queen goes from d1 to a4, guarding the pawn on c4, giving check.
The road to D90
- 1.d4 … 2...g6four earlier stops: A40, A45, A50, E60
- 3.Nc3E61 King’s Indian Defense
- 3...d5D80 Grünfeld Defense
- 4.Nf3D90
The position after 4.Nf3
White has brought out the knight on c3 and knight on f3; Black the knight on f6. Black could capture with dxc4. Undefended and attacked: the pawn on c4. Black is to move and has 31 legal moves.
Codes that branch off from D90
The reference lines of four other codes leave D90 from the position after 4...Bg7, each with its own moves.
| Code | Moves | Reference line |
|---|---|---|
| D91 | 5.Bg5 | Grünfeld Defense: Three Knights Variation, Petrosian System |
| D92 | 5.Bf4 | Grünfeld Defense: Three Knights Variation, Hungarian Attack |
| D94 | 5.e3 | Grünfeld Defense: Three Knights Variation, Burille Variation |
| D96 | 5.Qb3 | Grünfeld Defense: Russian Variation |
Closest boards in other codes
| Code | Line | Differs on |
|---|---|---|
| D15 | Slav Defense: Three Knights Variation | four squares: c6, g6, c7, g7 |
| D24 | Queen’s Gambit Accepted: Showalter Variation | four squares: c4, d5, g6, g7 |
| D37 | Queen’s Gambit Declined: Three Knights Variation | four squares: e6, g6, e7, g7 |
| D81 | Grünfeld Defense: Russian Variation, Accelerated Variation | four squares: d1, g1, b3, f3 |
| D82 | Grünfeld Defense: Brinckmann Attack | four squares: c1, g1, f3, f4 |
| E61 | King’s Indian Defense | four squares: g1, f3, d5, d7 |
| D70 | Neo-Grünfeld Defense: Goglidze Attack | five squares: b1, g1, f2, c3, f3 |
Where lines continue from here
Besides the codes above, they belong to D93, D95, D97, D98, D99.
Other move orders
- Grünfeld Defense: Three Knights Variation is also reached inside D85 Grünfeld Defense: Exchange Variation, Modern Exchange Variation, whose order is 1.d4 Nf6 2.Nf3 g6 3.c4 Bg7 4.Nc3 d5.