Figure 3-1 shows a sample confusion matrix. The first cell (upper left) is the number of times that affinity_card was actually 1 and was predicted to be 1. That numer is 516. The second cell (upper right) is the number of times that affinity_card was actually 1, but was predicted to be 0. That number is 25. The third cell (lower left) is the number of times that affinity_card was actually 0, but was predicted to be 1. That number is 10. The fourth cell (lower right) is the number of times that affinity_card was actually 0 and was predicted to be 0. That number is725.

This confusion matrix indicates that the predictions were correct 516 + 725 = 1241 times and incorrect 25 + 10 = 35 times.