The first signals given were "word signals;" that is, a word or a sentence called out so that the entire team might hear it and understand whether a kick or a run was to be made. Then, when signals became more general, "sign-signals" (that is, some motion of the hand or arm to indicate the play) were brought in and became for a time more popular than the word signals, particularly upon fields where the audience pressed close upon the lines, and their enthusiastic cheering at times interfered with hearing word signals. Of late years numerical combinations have become most popular, and as the crowd is kept at such a distance from the side lines as to make it possible for teams to hear those signals, they have proven highly satisfactory. The numerical system, while it can be readily understood by the side giving the signal, because they know the key, is far more difficult for the opponents to solve than either the old word signals or signs. Still, the ingenuity of captains is generally taxed to devise systems that shall so operate as never to confuse their own men and yet completely mystify the opponents throughout the game. Clever forwards almost always succeed in interpreting correctly one or two of the signals most frequently used, in spite of the difficulty apparent in the solution of such problems. The question as to who should give the signals is still a disputed one, although the general opinion is that the quarter-back should perform this duty. There is no question as to the propriety of the signals emanating from that point, but the discussion is as to whether the captain or the quarter should direct the play. Of course all is settled if the captain is himself a quarter-back, but even when he is not he ought to be able to so direct his quarter previous to the actual conflict as to make it perfectly satisfactory to have the signals come from the same place as the ball. It is in that direction that the eyes and attention of every player are more or less turned, and hence signals there given are far more certain to be observed. Moreover, it is sometimes, and by no means infrequently, necessary to change a play even after the signal has been given. This, if the quarter be giving the signals, is not at all difficult, but is decidedly confusing when coming from some other point in the line.