Each of the other North/South's scores are subtracted from the +620 score and the result entered in the point-differential cells. For each point differential, the IMP look-up table is used to determine the IMPs gained. For example, the differential of 720 equates to 12 IMPs, because it falls in the range of 600 to 740 in the IMP table. Adding the IMPs gained gives a total of 37. To determine the average IMPs gained, divide the total by the number of competitors (37 divided by 4) to arrive at 9.25 as the averaged cross-IMP score.