Published charts disagree with each other, because more than one route finishes most scores. The routes here follow four rules, applied in order.
Fewest darts wins. 40 is D20, not S20 D10.
Throw at beds you already aim at. A treble is a routine setup dart. A double or the bull used as a setup is a thin target thrown for no scoring benefit, so 120 is T20 S20 D20 rather than three double 20s.
Never finish on D1, D2 or D3 by choice. 122 is T18 T20 D4, not T20 T20 D1. The extra point of setup accuracy is worth far less than throwing at a double you can actually hit.
With three darts you are still scoring; with two you are finishing. On 150 you throw T20 T20 and take D15. On 61 you throw T15 and take D8, rather than T19 into D2.