When the start number and trial number of the 3D lottery are exactly the same, the lottery number of this lottery will change. This is because before the official lottery, the Welfare Lottery Center tested the lottery machine and the ball with the test machine number and recorded the corresponding results. In the actual official lottery, due to slight differences in various factors, the ball finally selected is slightly different from that in the experiment. If the starting machine number and the trial machine number are exactly the same, the final ball will be different from the previous test, which will affect the final winning result.