E24 Nimzo-Indian Defense: Sämisch Variation
E24 holds two named lines, all under the name Nimzo-Indian Defense. It leaves E20 (Nimzo-Indian Defense) with 4.a3. That final move, by the a-pawn, covers b4, opens a line for the rook on a1 and attacks the bishop on b4. Of all other reference positions, the board of E21 (Three Knights Variation) comes closest, four squares apart.
| # | White | Black |
|---|---|---|
| 1 | d4 | Nf6 |
| 2 | c4 | e6 |
| 3 | Nc3 | Bb4 |
| 4 | a3 |
Lines filed under E24
Both share the start 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 and then split two ways at White’s move 4.
| Name | After the shared start | Plies | At the end |
|---|---|---|---|
| Nimzo-Indian Defense: Sämisch Variation | 4.a3 | 7 | |
| Nimzo-Indian Defense: Sämisch Variation, Botvinnik Variation | 4.f3 d5 5.a3 Bxc3+ 6.bxc3 c5 7.e3 O-O 8.cxd5 Nxd5 | 16 | Black castled |
Nimzo-Indian Defense: Sämisch Variation, Botvinnik Variation
- 4.f3 The f-pawn advances to f3, covering e4 and g4.
- 4...d5 The d-pawn advances two squares to d5, covering c4 and e4, opening a line for the bishop on c8 and the queen on d8.
- 5.a3 The a-pawn advances to a3, covering b4, opening a line for the rook on a1, attacking the bishop on b4.
- 5...Bxc3+ The bishop on b4 takes the knight on c3, giving check.
- 6.bxc3 The b-pawn takes the bishop on c3, covering b4 and d4, opening a line for the bishop on c1.
The road to E24
- 1.d4 … 1...Nf6two earlier stops: A40, A45
- 2.c4A50 Normal Variation
- 3...Bb4E20 Nimzo-Indian Defense
- 4.a3E24
The position after 4.a3
White has brought out the knight on c3; Black the knight on f6 and bishop on b4. Black could capture with Bxa3, Bxc3+. Black is to move and has 33 legal moves.
Codes that branch off from E24
The reference lines of two other codes leave E24 from the position after 4.a3, each with its own moves.
| Code | Moves | Reference line |
|---|---|---|
| E26 | 4...Bxc3+ 5.bxc3 c5 6.e3 | Nimzo-Indian Defense: Sämisch Variation |
| E27 | 4...Bxc3+ 5.bxc3 O-O | Nimzo-Indian Defense: Sämisch Variation |
Closest boards in other codes
| Code | Line | Differs on |
|---|---|---|
| E22 | Nimzo-Indian Defense: Spielmann Variation | four squares: d1, a2, a3, b3 |
| E30 | Nimzo-Indian Defense: Leningrad Variation | four squares: c1, a2, a3, g5 |
| E32 | Nimzo-Indian Defense: Classical Variation | four squares: d1, a2, c2, a3 |
| E36 | Nimzo-Indian Defense: Classical Variation, Noa Variation | four squares: d1, c2, d5, d7 |
| E40 | Nimzo-Indian Defense: Rubinstein System | four squares: a2, e2, a3, e3 |
| A17 | English Opening: Anglo-Indian Defense, Hedgehog System | six squares: a2, d2, a3, b4, d4, f8 |
| D35 | Queen’s Gambit Declined: Normal Defense | six squares: a2, a3, b4, d5, d7, f8 |
Where lines continue from here
Three named lines filed under other codes pass through the position after 4.a3. All of them belong to the codes listed above.