A — the server tells the player that he may spawn and starts the stopwatch.
AB = time taken to transfer server's message (equals to
ping at that moment).
B — the player hears what the server said, spawns and begins racing.
BC = time taken by the player to stole the flag and to bring it to the other flag.
C — the player tells the server that he scored.
CD = time taken to transfer player's message (equals to
ping at that moment).
D — the server hears what the player said, notes the time and stops the stopwatch.
Thus,
actual race time going to maptop ≈ 2×
ping +
player's race time