Figure 9

Move evaluation and time series. Moves are numerically evaluated with respect to their impact on the overall puzzle completion. Moves that involves two pieces that should be connected fall under the progress category, moves that involves other pieces fall under the exploration category. Progress moves have a direct impact over the completion, while exploration move have an indirect impact. A move is valuated +1 if it creates a correct edges or destroy an incorrect edges, and −1 if it destroys a correct edge or create an incorrect edges. Given the time at which a move is performed, we obtain time series for each categories. We define an additional completion time series as the sum of the cumulative progress and exploration time series. More details can be found in Section 4.