In multiround you get 2 models to make 3 flights. There is a max time you are trying to achieve each round (varies due to motor class).
You have to decide if you want to fly all out on the first flight and maybe lose the model, leaving you with a single model for the last 2 flights. Or you could fly safe for the first flight and get your return and then fly away the 2 remaining flights.
If there is a tie after 3 rounds (more than one person maxed all flights) there is a fly off round.
For streamer the max times are:
Motor Multi-Round Maximum
1/8A 20 sec
1/4A 30 sec
1/2A 60 sec
A 120 sec
FAI A 180 sec
B 180 sec
C 240 sec
D 300 sec
E 300 sec
F 300 sec
G 300 sec
And here are the rules about multiround:
15.12 Multi-Round Events
Any duration event listing a multi-round maximum may be flown as a multi-round event. This must be indicated on the contest sanction. The weighting factor for the event shall be increased by 4 (four) in this case.
15.12.1 Number of Flights
Each contestant is initially allowed three official flights in a multi-round event. The Contest Director may designate that each flight must be flown in the time interval (round) designated by the Contest Director. Any model not flown in its designated round shall receive a zero score.
15.12.2 Number of Models
A contestant may enter no more than two models in a multi-round event for the purpose of making all official flights, including any necessary additional flights, except as stated in Rule 11.5.
15.12.3 Maximum Time
The official duration of each flight shall be calculated as follows: if the duration achieved exceeds the maximum time limit defined for that flight, the entry shall be awarded the maximum time limit; otherwise the entry shall be awarded its achieved duration in seconds. Timers may stop timing the flight after it has achieved the maximum time.
15.12.4 Scoring
Multi-round events shall be scored as follows: the official durations achieved by the contestant on the initial three official flights in the event shall be summed. If there is no tie for first place, then the contestant achieving the highest score is the winner. If there is a tie, contenders for first place shall be given the opportunity to make additional official flights (flyoffs) to determine the winner. The maximum time limit for a contestant's first additional flight shall be computed by adding a one minute increment (or, at the discretion of the Contest Director, a greater increment) to the maximum time limit for the event. For each subsequent additional flight made by a contestant, one additional increment shall be added to the previous maximum time limit. Additional flights shall be held in this manner until a winner is determined. Second through fourth places shall be distributed first among the other contenders in the flyoffs, and then among any other contestants having made qualified flights, on the basis of total computed score.
15.12.5 Return
The models in multi-round duration events need not be returned to the officials except as required by Rules 9.10 and 15.12.2.
15.12.6 Reduced Maximum Time
If unusual weather or field conditions are encountered, the Contest Director, with the concurrence of a majority of the contestants entered in the event, may lower the maximum time to a more reasonable value. The Contest Director must advise the Regional Contest Board that this has been done and the reasons for doing so.
