The ranking scores for each item are calculated by taking the values for the item (e.g. surrender values), placing them in order, and then allocating scores to each contract based on their position in the ranked list. If there are 10 contracts, then the top contract gets a score of 10, the next one gets 9 etc. If there are 20 contracts then the scores allocated will be 10, 9.5, 9.0, 8.5 etc.
In other words, the ranking system is fundamentally similar to dividing the contracts up into quartiles or deciles, but uses the full ordinal position to add extra precision to the ranking.
The scores for each selected ranking item are then weighted depending on whether you mark the item as Low, Medium or High importance. Medium-importance items are scored out 10, as described above. Low-importance and high-importance are adjusted so that they are marked out of 7.5 and 12.5 respectively.
The scores for each ranking item are then added together to produce an overall score for each contract.
The only exception to the above is desirability (i.e. contract features marked as desirable). Each feature that you choose is combined into a single Desirability score which is always treated as Medium importance overall.
N.B. All this means that the number of points for each contract are not “out of anything” in any significant sense. The maximum number of points which a contract can score depends on the number of ranking items that you choose. The percentages on the overall-score tab indicate how close each contract comes to the highest possible score given the ranking system you have defined.