420

420 is a solo training routine designed to systematically test your proficiency on every double segment of the dartboard. The goal is to start with a score of 420 and reduce it as close to zero — or as far below zero — as possible by hitting doubles D1 through D20, followed by the Bullseye, in sequence.

The game's name derives from the mathematical sum of all twenty doubles: 2 + 4 + 6 + … + 40 = 420. A player who hits each double exactly once across all rounds will finish on precisely zero, making it a clean benchmark for doubles accuracy.

A standard bristle dartboard and three darts are all that is required. No opponent is necessary — 420 is principally a solo practice routine, though two or more players may participate simultaneously by comparing final scores.

Prepare a scoresheet with a starting score of 420 and list 21 target rounds in order: Double 1, Double 2, Double 3, and so on through Double 20, followed by the Bullseye (inner bull, value 50). Each round should have space to record hits and the running score after that round.

Play proceeds through 21 consecutive rounds. In each round, the player throws three darts at the designated double target for that round. The sequence is strictly fixed:

• Round 1 – Double 1 (D1, value 2 per hit)
• Round 2 – Double 2 (D2, value 4 per hit)
• Round 3 – Double 3 (D3, value 6 per hit)
• Rounds 4–20 – Continue in ascending order through Double 20 (D20, value 40 per hit)
• Round 21 – Bullseye (inner bull, value 50 per hit)

For each dart that lands in the target double (or the inner bullseye in round 21), the value of that segment is subtracted from the player's running score. Darts that miss the target segment — including darts that land in the single, triple, or any other area of the board — score nothing for that throw and are simply disregarded.

Regardless of how many of the three darts hit or miss, the player always advances to the next round after throwing three darts. There is no elimination, no bust rule, and no penalty for missing. This ensures that all 21 targets are attempted every session, providing a complete diagnostic of the player's doubles accuracy.

For example, in Round 8 (Double 8, value 16 per hit), a player who lands two of three darts in D8 subtracts 32 from the running score (16 + 16). If all three darts miss D8, nothing is subtracted and the player moves on to Round 9 (Double 9).

Each successful hit on the designated target subtracts that segment's point value from the running total. The double segments and the bullseye carry the following values:

• Double 1 (D1): 2 points per hit
• Double 2 (D2): 4 points per hit
• Double 3 (D3): 6 points per hit
• Double 10 (D10): 20 points per hit
• Double 15 (D15): 30 points per hit
• Double 20 (D20): 40 points per hit
• Bullseye (inner bull): 50 points per hit

Since the player throws three darts per round, the maximum deduction in a single round equals three times the target's value. For instance, hitting all three darts in D20 subtracts 120 (3 × 40), while hitting all three bullseyes in the final round subtracts 150 (3 × 50).

A concrete example: a player begins Round 14 (D14, value 28) with a running score of 212. They land one dart in D14 and miss the other two. The deduction is 28, bringing their score to 184 entering Round 15.

If a player were to hit every double exactly once across the 21 rounds (one hit per round), the total deduction would be 2 + 4 + 6 + … + 40 + 50 = 470, which would bring the score to −50. A perfect session — hitting all three darts on every target — would yield a total deduction of 1,410 (three times the sum of all target values), producing a final score of −990.

The game concludes after all 21 rounds have been completed. The player's final score determines their performance level. A final score of exactly 0 indicates that every double was hit precisely once — an excellent benchmark. A negative final score means the player hit some doubles multiple times in their three-dart allowance, reflecting superior accuracy; the more negative the score, the better the performance.

When two or more players participate, the player with the lowest final score (i.e., the most negative or, failing that, the closest to zero) wins. In the event of a tied score, players may throw a single tiebreak round at the bullseye — each player throws three darts, and the player who hits more bullseyes wins. If still tied, the tiebreak is repeated until the tie is broken.

Competitive 420: Two or more players each complete the full 21-round routine independently (or alternating rounds), and compare final scores at the end. The lowest score wins. This transforms the solo exercise into a head-to-head contest while preserving its training benefits.

Range-Focused 420: Rather than completing all 21 rounds, the player selects a specific subset of doubles to target — for example, only D11 through D20 plus the Bullseye — to concentrate on weaker areas identified during full sessions.

Treble 420: A more demanding variant in which the targets are the treble segments (T1 through T20) plus the Bullseye instead of doubles. The starting score and sequence logic remain the same, but the higher difficulty of consistently hitting trebles makes this a significant step up.

420 is closely related to Bob's 27, another popular doubles training game. The key difference is that Bob's 27 features an elimination mechanic — a player whose score drops to zero or below is knocked out — which may cause them to never practice their weaker high-value doubles. 420 guarantees every double is attempted, making it a complementary diagnostic tool.

Use 420 as a diagnostic tool: Because every double is attempted in every session with no risk of elimination, 420 produces comprehensive data on your doubles accuracy. Record your hit rate for each double over multiple sessions to build a clear picture of your strengths and weaknesses.

Pay attention to the high-value rounds: Doubles 16 through 20 and the Bullseye carry the most scoring weight — a single hit on D20 is worth as much as hitting D1 and D2 combined (40 versus 2 + 4 = 6). Improving your consistency on these high-value targets has the greatest impact on your final score.

Pair 420 with Bob's 27: Use 420 to identify which doubles you consistently miss, then use targeted practice or Bob's 27 sessions to drill those specific segments under pressure. The two games complement each other — 420 diagnoses, Bob's 27 pressures.

Track your scores over time: A single session of 420 is informative, but the real value emerges over weeks and months. Plot your final scores on a chart. Steady improvement (scores trending lower) confirms your practice regimen is working; a plateau signals it may be time to adjust your approach.

Treat the Bullseye round as a bonus opportunity: At 50 points per hit, three successful bullseyes in Round 21 subtract 150 points — by far the largest possible single-round deduction. Staying composed and focused in this final round can dramatically improve your overall score, so practise your bull accuracy accordingly.