Double Out Rules in Darts: How Finishing Works

If you've played a few games of 501, you've probably experienced the frustration: you're down to 18, you hit a single 18, and... nothing happens. Your score stays at 18. That's because in standard darts, you can't just reach zero — you have to finish on a double. This one rule changes everything about how darts is played, and understanding it is the key to actually winning games.

What Does "Double Out" Mean?

Double out means your final dart of the game must land in the double ring — the thin outer band that runs around the entire board. Each segment has a double worth twice its face value:

• D20 = 40 points
• D16 = 32 points
• D10 = 20 points
• D1 = 2 points

The inner bullseye (the small red center dot, worth 50) also counts as a double. So if you have exactly 50 remaining, you can finish on the bull.

That's the core rule. Your last dart must hit a double that brings your score to exactly zero. Not close to zero. Not below zero. Exactly zero.

The Bust Rule

This is where beginners get caught out. If you score more than your remaining total — or reach exactly 1 (which is impossible to finish on a double) — your entire turn is busted. Your score resets to what it was before that turn.

Here's how it works in practice:

The bust rule applies mid-turn too. If your first dart busts you, the remaining two darts don't count and your score goes back to where it started.

The Different Finishing Formats

Not every game uses the same rules for starting and finishing. Here are the three common formats:

Double Out (Standard)

The default in competitive darts, pub leagues, and most casual play. You must finish on a double, but you can start scoring immediately — no special requirement for your first dart.

This is what you'll play 90% of the time. When someone just says "501" or "301," they almost always mean double out.

Straight Out (Open Out)

No double required to finish. If you have 18 left, you can hit single 18 and win. This format is common in:

• Beginner-friendly games
• Some electronic dartboard default settings
• Casual games where players agree to skip the double rule

Straight out is a good way to learn scoring and game flow without the pressure of hitting doubles. But it removes much of the strategy that makes darts interesting.

Double In, Double Out

The strictest format. You can't start scoring until you hit a double, and you must also finish on a double. Before your first double, all your darts count for nothing.

This is less common in standard play but shows up in some 301 variants and certain tournament formats. It makes 301 significantly harder and longer.

Every Double on the Board

There are 21 possible doubles — one for each number plus the bullseye. Here's the complete reference:

The doubles you'll use most are D20, D16, D10, D8, and D4 — because they form a natural "ladder" when you miss. Hit single 16 instead of D16? You're left on 16, which is D8. Miss that too? Single 8 leaves you on D4.

The D16 Ladder

This is why D16 is the most popular finishing double in professional darts. Watch what happens when you miss:

1. Aim at D16 (32) — miss into single 16 → left on 16
2. Aim at D8 (16) — miss into single 8 → left on 8
3. Aim at D4 (8) — miss into single 4 → left on 4
4. Aim at D2 (4) — miss into single 2 → left on 2
5. Aim at D1 (2) — finish

Each miss drops you cleanly to the next double down. No awkward numbers, no odd-number traps. That's why experienced players set up 32 whenever possible.

Setting Up Your Double

The real skill in double out isn't hitting the double — it's getting to the right number so you can attempt one. This is called "setting up" or "leaving" a finish.

Keep It Even

The golden rule: always try to leave yourself an even number. An even number means you can go straight for a double. An odd number means you need to hit a specific single first to get back to even, wasting a dart.

When you have three darts left and an even number at or below 40, you have three shots at your double. With an odd number, you only get two shots because the first dart has to fix your score.

Know the Key Leave Numbers

When you're above 40 (the highest single-dart finish besides the bull), you need to use one or two darts to get down to a double. The best numbers to aim for:

• 32 (D16) — the best leave in darts for the reasons above
• 40 (D20) — biggest target on the outer ring
• 36 (D18) — clean double, miss goes to a manageable number
• 24 (D12) — another clean even number
• 16 (D8) — already on the D16 ladder

For a complete breakdown of how to plan your finishes from any score, see our 501 checkout chart.

Why Double Out Makes Darts Better

If you're a beginner wondering why this rule even exists, here's the thing: double out is what turns darts from a simple subtraction game into a strategic one.

Without the double-out rule, 501 would just be "throw at triple 20 until you reach zero." The better scorer would win almost every time. Doubles add a layer where accuracy under pressure matters, where you have to plan ahead, and where a player who's behind can steal a leg because their opponent can't close out.

Some of the most dramatic moments in professional darts happen on doubles. A player sitting on 40 with three darts in hand, needing D20 to win the match — that pressure doesn't exist in straight out.

Practicing Doubles

Doubles are worth dedicated practice time. Here are three focused routines:

Around the Board on Doubles

Go around the board hitting each double in order: D1, D2, D3... through D20, then Bull. Track how many total darts it takes. Professional players can do this in under 60 darts. Beginners might take 200+. Either way, it's the best way to build familiarity with every double on the board.

Pressure Doubles

Pick a double (start with D16). Give yourself 9 darts (3 turns) to hit it. Track your success rate over 10 attempts. Once you're hitting 6 or 7 out of 10, move to a harder challenge: 6 darts to hit the double.

Checkout Simulation

Start at a random number between 41 and 100. Finish the checkout in as few darts as possible. This practices both the setup and the finish together, which is closer to what you'll actually do in a game.

Common Double Out Mistakes

Not planning your finish early enough. Once you're below 170, you should already be thinking about which double you want to end on. Don't wait until you're on 48 to start planning — know that 48 is 16 + D16 before you throw.

Leaving odd numbers. If you have 85 remaining, throwing T20 (60) leaves 25 — an odd number. Throwing T19 (57) leaves 28 (D14) — much better. Think about what you'll leave, not just what you'll score.

Always going for D20. D20 is fine, but it's not always the best option. D16 has a better miss ladder. Pick a double you're genuinely comfortable with and set it up consistently.

Giving up on your turn too early. If you bust on your first dart, that's it — turn over. But if your first dart leaves you on an odd number with two darts remaining, you still have options. Hit a single to get even, then go for the double. Don't throw your remaining darts at random.

Start Finishing

The double out rule is what gives darts its edge. It's the reason a 501 leg can swing in the final throw, and it's the skill that separates players who score well from players who actually win. Now that you understand how it works — the bust rule, setting up your finishes, and the power of the D16 ladder — it's time to put it into practice.

Start a 501 game on Dartsy and pay attention to your finishing. The app shows you the optimal checkout path when you're in range, so you can learn the best routes as you play. The more you practice finishing on doubles, the more natural it becomes — and the more games you'll close out.