170 Checkout — The Big Fish (T20, T20, Bull)
The 170 checkout uses a three-dart route with two consecutive throws at T20. At this score, controlling the first dart is the central challenge — everything else in the route depends on where T20 lands. A clean execution through T20 → T20 → DBull leads directly into DBull, a double that is less forgiving than the elite options — arriving at it cleanly through the route is what makes it manageable.
The preferred miss direction on T20 from 170 is toward 5. Landing there leaves 165 — a position that still carries a realistic path to the close. The 1 side leaves 169 and a harder problem. Players who pay attention to miss geometry on their primary scoring targets consistently produce better outcomes from imperfect darts, which is where most of the marginal gains in competitive 501 are actually found — not in perfect throws, which are the same for everyone, but in where the imperfect ones land.
Players who are reliable at finishing 170 in competition have usually identified and eliminated one specific failure pattern from their game: the tendency to respond to what just happened rather than commit to what comes next. If the first dart misses, the instinct is to adjust — to be more careful, to aim more precisely, to compensate. That instinct is the source of most dropped legs on 170. The route provides the continuation from any reasonable first-dart outcome. Trusting the route rather than overriding it mid-visit is the discipline that converts practice form into match results.
The decision to commit to T20 should be complete before the player leaves the throwing position from the previous dart. Arriving at the oche having already decided removes one source of last-moment disruption. In competitive darts, the checkout is where matches are decided. The ability to execute under pressure on scores like 170 is the defining skill at the highest level. The focus on 170 should be on setting the route cleanly, not forcing an early finish. Patience at this score is a genuine competitive advantage. The most important moment in finishing 170 is not the throw itself — it is the decision to commit made before the throw begins. On 170, the dart that misses under pressure is usually released too late and too slowly. The player held on fractionally longer than normal. That is the entire cause of the miss.
Against an opponent who can win next visit, the bull route on 170 offers the fastest close available. That speed is worth the reduced recovery margin when the match situation demands urgency.
Route Comparison & Target Selection
Primary: T20 → T20 → DBull
treble 20 (60), treble 20 (60), closing on bull (50) — direct bull finish
Avoid 25 on this route. A miss into the outer bull removes the finish and means the leg must be rebuilt.
Miss Geometry, Route Structure & When to Use the Alternate
The geometry around treble 20 is the most punishing on the board for missed triples. The 5 and the 1 sit either side of it — neither useful as a recovery segment from 170. A miss left into 5 leaves 165; a miss right into 1 leaves 169. The route opens on treble 20 because the scoring efficiency justifies it when the darts are landing in the bed. When they are not — when grouping drifts low consistently — switching to treble 19 corrects the geometry. The 3 and 7 that flank the 19 score more than the 5 and 1, and more often leave a position from which the leg can still be closed cleanly. That structural upgrade is the reason the switch is taught as a deliberate skill, not a fallback. Making the decision before stepping to the oche, and executing it with full commitment, is the competitive standard. Beyond the opening dart geometry, the route from 170 runs T20, T20, DBull. Two consecutive throws at the same target before the close place grouping consistency at the centre of the execution requirement. Where routes with different setup darts allow for slight adjustments between throws, this one rewards the player who treats both T20 darts as a single committed decision repeated rather than two separate aim events. That approach — throw once, repeat the throw — is what produces tight, predictable grouping on back-to-back visits to the same segment under match conditions.
When and Why to Use This Route
This route is correct when the opponent can win on their next visit and a direct finish is needed. The bull's value is its speed — it ends the leg without building toward a standard double. That speed is the reason to use it. When urgency is absent, the standard route to a reliable double is the better structure.
The route works by converting a complex finish into a single, high-commitment action. Hitting the bull ends the leg immediately. Missing it creates a more complex recovery than a missed standard double would. That asymmetry is exactly why the bull route is correct in specific situations — when the match demands the fastest close and the player's confidence at the bull is genuine — and why it requires the same deliberate decision-making that any other high-consequence route demands.
Why Players Miss This Finish
The bull on 170 is missed because of guided delivery. Players who approach the bull with a slow, deliberate, carefully aimed throw miss it more consistently than those who throw it at the same pace used for every other dart in the visit. The bull does not reward careful aim — it rewards committed release. A dart that is thrown at the bull with the same arm speed and grip as a standard treble will fly straighter and land more accurately than one that was guided toward the centre with extra deliberateness. The most common instruction — 'throw it nicely' — is the exact instruction that causes the miss.
Improving bull accuracy at 170 in match conditions requires two things: throw it more often in practice under pressure, and stop aiming it. Aiming the bull — treating it as a target that needs to be carefully guided toward — is the behaviour that causes most competitive bull misses. The bull responds to the same committed, unremarkable throw used for any other target. Practice it until that throw is automatic, and the match environment stops changing it.
Practice
The most effective practice structure for the 170 checkout is to run T20 → T20 → DBull as a complete sequence and track the breakdown point. Where does the visit most often fail — on T20, on T20, or approaching DBull? Once the breakdown point is identified, give that dart specific attention: practise it in isolation to diagnose the problem, then reintegrate it into the full sequence. Most players practise the dart they are most comfortable with. The fastest improvement comes from practising the one that is failing.
Practise 165 and 169 explicitly as part of the 170 practice block. These are the scores left by the two miss directions from T20 — 165 via 5 and 169 via 1. A player who knows both continuations and has thrown them recently does not need to think when one of them appears in a match. The visit continues. That automaticity is what keeps legs alive after an imperfect first dart. Pair the full route practice with recovery reps so neither feels unfamiliar when the match requires it.
