Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
In five Qualifying round will started 80 riders and to Semi-finals will qualify top 6 from each meetings. This 30 riders and 2 riders from Semi-final' host federations will started in two Semi-finals. The top 7 riders from both SF will automatically qualify for all Final meetings.
Riders
There will be fourteen permanent riders (riders placed 1st to 7th in both semi finals will automatically qualify for all Final meetings). Two Wild Card riders will be nominated to each final meeting (approval and nomination by CCP Bureau). Two Track Reserve riders will be nominated by national federation. In case of the absence of one or more riders in the final meetings, the first available Qualified Substitute rider or riders will be elevated for that meeting, and take the place(s) of the relevant missing rider(s).
Permanent riders
Top 7 riders from Semi-final One in Žarnovica, Slovakia
m - exclusion for exceeding two minute time allowance •
t - exclusion for touching the tapes •
x - other exclusion •
e - retired or mechanical failure •
f - fell •
ns - non-starter •
nc - non-classify
m - exclusion for exceeding two minute time allowance •
t - exclusion for touching the tapes •
x - other exclusion •
e - retired or mechanical failure •
f - fell •
ns - non-starter •
nc - non-classify
m - exclusion for exceeding two minute time allowance •
t - exclusion for touching the tapes •
x - other exclusion •
e - retired or mechanical failure •
f - fell •
ns - non-starter •
nc - non-classify
m - exclusion for exceeding two minute time allowance •
t - exclusion for touching the tapes •
x - other exclusion •
e - retired or mechanical failure •
f - fell •
ns - non-starter •
nc - non-classify
gate A - inside
gate B
gate C
gate D - outside
Silver medal run-off
Because after the last heat was a tie between second and third placed riders, a run-off was decided about silver and bronze medals.
The meeting classification will be according to the points scored during the meeting (heats 1–20). The total points scored by each rider during each final meeting (heat 1–20) will be credited also as World Championship points. The FIM Speedway Under 21 World Champion will be the rider having collected most World Championship points at the end of the series. In case of a tie between one or more riders in the final overall classification, a run-off will decide the 1st, 2nd and 3rd place. For all other placings, the better-placed rider in the last final meeting will be the better placed rider.