The procedure is the same as for his own courses of action (Section II). However, since the enemy's appropriate effect desired, if deducible at all, is often only an approximation, the test for suitability is usually less rigid or absolute than for the commander's own courses of action. By the same token, since the enemy's fighting strength will usually include elements of conjecture and hypothesis, the test for feasibility may be less reliable than when applied to the commander's own courses. In fact, if there are any reasonable doubts as to feasibility of an enemy course of action, it is properly retained for further consideration. The same considerations and the same safeguard apply with respect to acceptability of the consequences. D. Listing Retained Enemy Courses of Action. All enemy courses of action which, after test, are retained for further study are now listed by the commander. While it is manifestly of advantage to the commander if the number of enemy courses can reasonably be reduced to only a few or even to one, it is important that no material enemy capability be neglected because of undue restriction of the field. The previous analysis will have indicated, at least, in some cases, the degree of suitability and feasibility, and will have enabled the commander to form a considered opinion as to any preference, from the enemy viewpoint, on the basis of consequences as to costs. In many instances, therefore, it will be possible to arrange retained enemy courses in order of priority, i.e., the more likely being listed before the less likely. In case of doubt, the higher priority is awarded by the commander to enemy courses which are more dangerous from his (the commander's) point of view. In other instances, no priority can properly be indicated. As a result of this study, the commander may now be able to combine certain enemy courses. In any case, he closes this portion of the estimate with a list of them, classified so far as he finds justifiable, and thus made available for further effective use in the estimate. SECTION IV SELECTION OF THE BEST COURSE OF ACTION The extent to which detail is desirable in Section IV of the Estimate will vary with the nature of the problem (page 95). Experience usually demonstrates, however, that an estimate in only the necessary detail escapes the danger inherent in undue detail which would tend to befog the main issues. As the commander proceeds with his estimate, he will recognize the need for additional examination into details, and will conduct such examination accordingly. A. Analysis and Comparison of Retained Courses of Action.