Short answer: the Big Fish in darts is the 170 checkout: treble 20, treble 20, bullseye. It is famous because 170 is the highest standard three-dart finish in double-out darts. Anything above 170 cannot be finished in three darts, and 169 is lower but still a bogey number.
Last reviewed: 23 August 2026. This guide assumes standard steel-tip x01 double-out rules. Casual, soft-tip and house formats can use different finishing rules, but the classic “Big Fish” phrase refers to 170.
Why 170 is called the Big Fish
The nickname comes from 170 being the biggest finish available. Sky Sports describes the Big Fish as the highest possible checkout in darts, taken by two treble 20s and the bullseye. Darts501 gives the same route and notes that 170 is the highest checkout on a standard dartboard.
The phrase is part of darts commentary language. When a player leaves 170, commentators know the exact route immediately: T20, T20, bull. The nickname adds drama because the route is simple to say but extremely hard to complete.
The Big Fish route
| Dart | Target | Score | Remaining |
|---|---|---|---|
| 1 | Treble 20 | 60 | 110 |
| 2 | Treble 20 | 60 | 50 |
| 3 | Bullseye | 50 | 0 |
Two treble 20s create the chance. The bull closes it. There is no spare dart, no alternate double after the two trebles, and no easy rescue if the first dart misses the treble bed.
Why 171 or higher cannot be finished
A checkout has to end on a double or bull. The highest one-dart finish is bull, worth 50. That means the first two darts must leave 50 or less, and the total must still add exactly to the remaining score.
For 170, the maths works: 60 + 60 + 50. For 171, even two treble 20s leave 51, and there is no single finishing dart worth 51. Scores above 170 have the same problem. They can be scored in some cases, but they cannot be checked out in three darts under double-out rules.
Why 169 is not a smaller Big Fish
169 is lower than 170, but it is a bogey number. That means it cannot be finished in three darts. PDC Europe lists 169 among the bogey numbers below 170 that cannot be checked in three darts. Darts501 lists the same bogey-number group: 169, 168, 166, 165, 163, 162 and 159.
This is why 170 is so iconic. It sits at the absolute top of the finishable range, while the number immediately below it is unfinishable. That contrast makes the Big Fish easy to remember.
Why the bull finish changes the pressure
Many big checkouts finish on a familiar double such as double 20, double 18 or double 16. The Big Fish ends in the centre of the board. That changes the sightline and rhythm. After two darts thrown at the top of the board, the player has to reset down to bull.
The bull is also psychologically different. A missed double may still leave a nearby double or single recovery in some finishes. A missed bull on 50 normally leaves the leg alive for the opponent. The final dart has to be precise.
What happens if the first dart misses?
If the first dart lands in single 20, the 170 checkout is gone because 150 cannot be finished with two darts. If the first dart lands in treble 5 or treble 1, the visit becomes a recovery problem rather than a checkout attempt.
This is where good players separate themselves. They do not just admire the missed Big Fish. They immediately switch to setup thinking: what can I leave, and what gives me the best chance next visit?
How to practise the Big Fish properly
Practise it in blocks. First, throw three darts at treble 20 and record how often you hit two or more. Then practise bull finishes from 50. After that, combine the full 170 route.
A better match drill is to start every visit on 170. If the first dart hits treble 20, continue the checkout. If it misses, switch instantly to setup mode and try to leave a finish. This trains the real match skill: knowing when the dream shot is gone and making the next visit easier.
Recovery after missed first darts
The Big Fish is a checkout attempt for exactly as long as the route remains alive. If the first dart hits single 20, the player has 150 left with two darts. That cannot be finished, so the task changes. A good player may use the next two darts to leave a preferred finish rather than keep forcing a dead route.
If the first dart hits treble 1, the score moves to 167. That is still a finish if two darts remain? No: 167 needs three darts, usually T20, T19, bull. With only two darts left, the player is now setting up. If the first dart hits treble 5, the remaining score is 155, again not finishable with two darts. The visit has become damage control.
This is why a useful Big Fish practice routine includes misses. If you only practise the perfect route, you practise a highlight. If you practise the miss response, you practise match darts.
Match situation matters
If your opponent is sitting on a double, a missed first treble on 170 should usually trigger a high-quality setup attempt. You may only get one more visit, so leaving a clean finish matters. If your opponent is far back, you might take a more aggressive second dart to keep pressure on the score.
The scoreboard changes the value of risk. At professional level, players will nearly always attack 170 because it is the biggest finish and the route is clear. At club level, the best choice after a miss is often the one that avoids leaving a bogey or an awkward finish next visit.
Why 170 feels different from 167 and 164
Other large checkouts are possible, but they have different personalities. 167 is usually T20, T19, bull. It needs a switch after the first dart. 164 is often T20, T18, bull. It also needs movement around the board. 170 is visually simpler: stay on treble 20 twice, then bull.
That simplicity is part of the drama. Everyone watching knows whether the first dart has kept the route alive. Everyone knows what the second dart means. By the time the player is on bull, the whole room understands the shot.
How to leave the Big Fish
Leaving 170 can be smart because it is finishable. Leaving 169 is not. If you are above 170 and cannot finish this visit, setup thinking matters. From 230, scoring 60 leaves 170. From 229, scoring 59 leaves 170. From 231, scoring 61 leaves 170, but that route depends on what you are comfortable hitting.
The principle is simple: if you cannot finish, leave a finish. Strong players know the difference between a big-looking score and a useful leave. A score that leaves 170 keeps the leg alive. A score that leaves 169 removes the immediate checkout threat.
A 20-minute Big Fish session
Spend five minutes throwing only at treble 20. Count visits where you hit at least two trebles. Spend five minutes on bull from 50. Count only clean bull finishes. Spend five minutes on full 170 attempts. Then spend five minutes starting on 170 but requiring a setup leave after any missed first dart.
This final block is the most valuable for normal players. It trains the emotional reset. The first treble misses, the highlight is gone, and you still have to make a sensible choice. That is where legs are often won or lost.
Beginner, pub player and advanced view
| Player level | What to learn from 170 | Useful target |
|---|---|---|
| Beginner | How checkout routes work | Learn why bull can finish |
| Pub player | Setup after missed trebles | Leave a clean finish |
| Advanced | Pressure transition from T20 to bull | Practise full 170 attempts |
Common mistakes
- Thinking 171 is close enough: it is above the checkout ceiling.
- Forgetting 169 is a bogey: lower does not always mean finishable.
- Practising only successful routes: you also need the recovery after a missed first treble.
- Rushing the bull: the final dart needs a reset, not a panicked continuation.
Big Fish myths
Myth one: 170 is just another high checkout. It is not. It is the ceiling. The numbers above it cannot be checked out in three darts, so 170 has a special place in the game.
Myth two: 169 should be easier because it is lower. It is lower, but it is not finishable in three darts. That is why checkout knowledge matters more than raw number size near the end of a leg.
Myth three: the bull is just a bigger double. The bull scores 50 and can finish, but it feels different from the outer doubles. The sightline, target shape and pressure are different, especially after two darts at treble 20.
Route comparison: 170, 167 and 164
| Finish | Common route | What changes |
|---|---|---|
| 170 | T20, T20, Bull | No switch until the final dart. |
| 167 | T20, T19, Bull | Requires a treble switch before bull. |
| 164 | T20, T18, Bull | Another treble switch and bull finish. |
This comparison shows why 170 is both clean and severe. You do not need to switch after the first treble, but you do need two perfect darts in the same small bed before facing bull. The route is easy to remember and hard to execute.
Equipment and setup notes
Big Fish practice needs a board with a clean treble 20 and bull area. If either section is worn, your feedback becomes unreliable. Browse dartboards if the scoring beds are tired, dart sets if your grouping is inconsistent, and darts accessories for flights, stems, mats and practice essentials.
Visual guide: how to apply this at the board
Related reading
For checkout context, read the hardest checkout in darts and impossible three-dart scores. For perfect-leg context, see how hard a nine-dart finish is and the fewest darts to win 501.
Sources used
- Sky Sports darts glossary explaining Big Fish.
- Darts501 checkout chart and 170 route.
- PDC Europe glossary note on 170 and bogey numbers.
- myDartpfeil checkout explanation of 170 and 169.
- Darts Checkout Assistant bogey-number explanation.
Bottom line
The Big Fish is the 170 checkout: T20, T20, bull. It is famous because it is the highest standard three-dart finish, because 171 and above cannot be finished, and because 169 is lower but still unfinishable.
FAQ
Can you finish 170 in darts?
Yes. The standard route is treble 20, treble 20, bullseye.
Why is 170 called the Big Fish?
Because it is the biggest checkout available in standard double-out darts.
Can you finish 171?
No. There is no three-dart route from 171 that ends legally on a double or bull.
Is the Big Fish harder than a nine-darter?
No. A nine-darter is harder overall, but the Big Fish is one of the hardest single-visit finishes.
