Chessy
Sicilian Four Knights: Ndb5 – Survival Guide for Black
After 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6, White has a sharp idea: 6.Ndb5, threatening to jump into d6 and disrupt your position. You answer with 6...d6, blocking the knight and keeping the centre fluid. Now it's White's turn, and the engine says +0.29 — a tiny edge for your opponent. That sounds worrying, but the statistics tell a different story: across over 18,800 games at this exact position, Black actually wins 48.4% of the time, edging out White's 48.1%. This is no trap to fear — it's a fighting Sicilian where you can play for a win if you know how to respond. Let's break down exactly what to do.
Play the Sicilian: Four Knights: Ndb5 against the engine
Free, no signup — you play black, the engine adapts to your level.
Ready to test your knowledge? Play through the position against the interactive engine below — it adapts to your moves and helps you learn exactly how to punish
Create a free account →The Critical Moment: White's Best Move Is Bf4
The engine thinks White's strongest move here is Bf4, building pressure before you can organise your centre. The idea is simple: after Bf4 e5 Bg5 a6, White forces you to chase the knight while keeping the bishop on an active diagonal. This line scores 58.4% for White across 6,029 games — the highest White win-rate of any continuation. So you need to know what you're doing from the very first move. Your task is to hold the centre and develop calmly. When White plays Bg5 in reply to ...e5, you have ...a6 ready to ask the knight where it's going. The position stays tight, but you are not worse here if you play accurately.
The Most Common Moves (and Why Most Are Inaccuracies)
The most popular move by White in this position is Bg5, played over 7,500 times — but it's a mistake. The engine says Bg5 loses about 0.8 pawns of advantage compared to Bf4, and White only scores 44.8% from here, which is actually below average for your opponent. That's great news for you as Black. Other common inaccuracies include: - Be2 (played 1,061 times): loses ~0.6 pawns, White scores 40.7% — an even better result for you. - Be3 (844 games): also loses ~0.6 pawns, White scores 41.1%. If your opponent picks any of these, you are already doing well. The only move you need to respect is Bf4, which is why this drill focuses on that exact line.
What You Are Fighting For: The Central Structure
After 6...d6, the pawn on d6 gives you a solid foothold in the centre. Your plan is to follow up with ...e5 (kicking the bishop if it went to f4, or simply continuing development), then ...Be7, ...0-0, and standard Sicilian play on the queenside. The knight on b5 looks scary but it isn't stable — you can chase it with ...a6 at the right moment. Meanwhile, your kingside is safe and you have natural development. The key principle: don't rush. Complete your development, keep the centre solid, and wait for White's aggressive knight to commit somewhere. In many games, White overpresses and you end up with the better position.
The Statistic That Should Give You Confidence
Look at the numbers again. In 18,839 games, Black wins 48.4% and White wins 48.1%. That is essentially equal results over a massive sample. This opening is not a forced win for either side, but it clearly does not favour White in practice the way the +0.29 evaluation might suggest. Why? Because the position is tricky for White to handle too. The knight on b5 can become misplaced if Black responds accurately. Many White players don't know the exact follow-up and drift into one of those inaccuracies (Bg5, Be2, Be3). Your job is simple: know the refutation, stay solid, and let your opponent prove they know what they're doing. Often, they won't.
Results across 18,839 Lichess games
| Most-played continuation | Games | White wins |
|---|---|---|
| Bg5 | 7,585 | 44.8% |
| Bf4 | 6,029 | 58.4% |
| Be2 | 1,061 | 40.7% |
| Be3 | 844 | 41.1% |
| Bd3 | 719 | 40.2% |
| e5 | 587 | 46.0% |
Frequently asked questions
What is the main idea behind 6.Ndb5 in the Sicilian Four Knights?
White's knight jumps to b5 threatening to go to d6, which would be a strong outpost. With 6...d6 you block that square and leave the knight slightly awkward. The idea is that White wants to force you into passive moves, but if you know the correct setup it backfires and the knight becomes a target.
Which White move should I fear most after 6...d6?
The engine's top choice is Bf4, which scores 58.4% for White. After Bf4 e5 Bg5 a6, you need to be ready to chase the knight. Most other popular moves like Bg5, Be2, or Be3 are inaccuracies that lose White's opening advantage. As long as you respect Bf4, you'll be fine.
Is the Sicilian Four Knights Ndb5 a good opening for beginners?
Yes — the statistics show Black wins just as often as White in practice. The positions are principled and teach you important Sicilian themes: central control with ...d6 and ...e5, chasing enemy pieces with ...a6, and solid development. Just avoid rushing and you'll get a playable middlegame every time.
What happens if White plays Bg5 instead of Bf4?
Bg5 is the most common move in the database (7,585 games), but it's an inaccuracy that loses about 0.8 pawns of advantage. White only scores 44.8% from here — a below-average result. You can simply develop normally with ...Be7 and ...0-0, and you'll already have slightly the easier position.
How many games feature the Sicilian: Four Knights: Ndb5?
Over 18K Lichess games have reached the Sicilian: Four Knights: Ndb5 position. White wins 48.1%, Black wins 48.4%, with 3.5% draws — based on real rated games.