In practice, however, and in a definite problem, the number of factors can be kept down by assuming average conditions of weather, using the fairly well-known enemy force that would appear in practice, and playing games in which the only important variable is the kind of vessel in question. For instance, in the endeavor to ascertain the value of the battle cruiser, games can be played in which battle cruisers are only on one side, or in which they are more numerous, or faster or more powerful on one side than on the other. Naturally, the games cannot be as valuable practically as they otherwise would be, unless they consider the amount of money available. For instance, if games are played to ascertain the most effective number and kinds of craft for which to ask appropriations from Congress at next session, the solution, unless a money limit were fixed, would be impossible. In other words, the amount of money to be expended must be one of the known or assumed factors in the problem. As this amount can never be known, it must be assumed; and, in order that the whole value of the games may not be lost, in case the amount assumed were incorrect, it is necessary to assume a number of possible sums, the upper limit being above the probable amount to be received, and the lower limit below it, and then work out the answer to the problem, under each assumption. Of course, this procedure would be laborious, but most procedures are that bring about the best results. Suppose that such a procedure were followed for, say, a year, and that a number of plans, all worked out, were presented to Congress when it met: plan No. 1, for instance, consisting of such and such craft showing (according to the results of the games) the best programme, if $100,000,000 were to be appropriated for the increase of the navy; plan No. 2, if $90,000,000 were to be appropriated; plan No. 3, if $80,000,000 were to be appropriated, and so on. Each plan being concisely and clearly stated, and accompanied by drawings, sketches, and descriptions, Congress could easily and quickly decide which plan it would adopt.