Game The short answer
Across 4 independent positions, a knight on the rim was never the best move. The gap to the best move averaged 0.69 pawns and never exceeded 1.10. Not losing, then — but consistently a little worse.
What we are testing
"A knight on the rim is dim" is one of the best-known sayings in chess. A knight in the centre covers up to eight squares; on the edge it covers less than half that. But how much does the destination alone change the evaluation, when the move itself is the same "develop a knight"?
How we tested it
Testing a rule of thumb in one position cannot tell you whether you are seeing the rule or just that position. So we picked 4 positions of different character — open and closed, White to move and Black to move. In each one, every candidate is played and the resulting position is searched. All the numbers are real output, not estimates.
Position by position
| Position | Best move | Move tested | Gap |
|---|---|---|---|
| After 1.e4 e5 2.Nf3 Nc6 (White to move) | Bb5 +0.42 | Na3 −0.68 | 1.10 |
| A knight on move one (White to move) | Nf3 +0.32 | Nh3 −0.46 | 0.78 |
| In the Queen’s Gambit (White to move) | Nc3 +0.29 | Na3 −0.35 | 0.64 |
| When the rim is right (Black to move) | Bb7 −0.29 | Na5 −0.53 | 0.24 |
Position 1｜After 1.e4 e5 2.Nf3 Nc6 (White to move)
1.e4 e5 2.Nf3 Nc6
The best move was Bb5 (+0.42). Na3 scored −0.68, a gap of 1.10.
Tap a candidate move to change the board
| Move | Evaluation | Diff vs best |
|---|---|---|
| Bb5 | +0.42 | best |
| Bc4 | +0.28 | −0.14 |
| Nc3 | +0.24 | −0.18 |
| d4 | +0.18 | −0.24 |
| Na3 | −0.68 | −1.10 |
| Nh4 | −4.08 | −4.50 |
Position 2｜A knight on move one (White to move)
The starting position
The best move was Nf3 (+0.32). Nh3 scored −0.46, a gap of 0.78.
Tap a candidate move to change the board
| Move | Evaluation | Diff vs best |
|---|---|---|
| Nf3 | +0.32 | best |
| Nc3 | +0.13 | −0.19 |
| Nh3 | −0.46 | −0.78 |
| Na3 | −0.57 | −0.89 |
Position 3｜In the Queen’s Gambit (White to move)
1.d4 d5 2.c4 e6
The best move was Nc3 (+0.29). Na3 scored −0.35, a gap of 0.64.
Tap a candidate move to change the board
| Move | Evaluation | Diff vs best |
|---|---|---|
| Nc3 | +0.29 | best |
| Nf3 | +0.27 | −0.02 |
| cxd5 | +0.19 | −0.10 |
| Na3 | −0.35 | −0.64 |
| Nh3 | −0.35 | −0.64 |
Position 4｜When the rim is right (Black to move)
1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3
The best move was Bb7 (−0.29). Na5 scored −0.53, a gap of 0.24.
Tap a candidate move to change the board
| Move | Evaluation | Diff vs best |
|---|---|---|
| Bb7 | −0.29 | best |
| Re8 | −0.37 | −0.08 |
| Be6 | −0.43 | −0.14 |
| Na5 | −0.53 | −0.24 |
| Nb8 | −0.61 | −0.32 |
| h6 | −0.61 | −0.32 |
Where the difference comes from
Na3 is not weak only because it covers fewer squares. The engine line is 3...Bxa3 4.bxa3: Black trades a bishop for the knight and wrecks White’s pawn structure. The edge square happened to sit on a bishop’s diagonal — a concrete problem, not a vague one.
Nh4 is worse than any proverb: 3...Qxh4 simply wins the knight (the d8–h4 diagonal is open). The large drop is just material loss showing up in the number.
Exceptions
This does not mean an edge knight is always bad; it is the result in this position. In real games the rim can be a useful staging square on the way back to the centre.
A proverb tells you which moves to check first. It is not a ban. What matters is reading what the opponent can do right after the move.
What this does and does not show
- It shows: what the engine returned for these 4 positions, with every candidate searched to depth 20. The numbers are the raw output; none of them were adjusted afterwards.
- It does not show: anything about "all positions" — a sample of 4 is a very small slice of chess.
- The assumption: an evaluation assumes best play from both sides. Over the board, an inaccurate reply changes everything.
- Reproducing it: the positions and candidates live in
tools/generate-chess-analysis.mjs, the results inassets/chess-analysis.json. The same settings give the same numbers.
What to remember at the board
- The same knight scores very differently depending on the square
- Na3 loses out to Bxa3, which ruins the pawn structure
- Nh4 simply drops a piece to Qxh4
- The rim is not always bad — it is bad here
Try it yourself
You can try the same idea in a real game. Every move is scored by the engine, so the difference between principled and careless moves shows up immediately.