With all signals given by the catcher to the different in-fielders the short-stop must be perfectly familiar, in order that he may be prepared to do his part. If there is to be a throw to second or third he should know it, so that he can be ready to back up in case the throw is wide or breaks through the baseman's hands. So, too, he must know when to expect a throw if he himself be covering second. In all cases where a runner is caught between bases, the short-stop must take part. If the play is between first and second or between second and third, he and the second baseman alternate in backing one another up on one side of the runner, while the other baseman and the pitcher do the same on the other side. If it is between third and home, he and the third baseman attend to one side, while the catcher and pitcher look after the other. In every case the base runner should be run down as quickly as possible, and always toward the base farthest from the home plate, so that if an error is made the runner will gain no advantage. In backing up other fielders a short-stop may be of great service, and he should do this in every possible case, no matter where the play may be. But the positions which he is specially bound to back up are the second and third bases, not only on all throws from the catcher, but from any other fielder, where it is possible for him to get in line with the throw. He must not get too close to the baseman but keep a sufficient distance back of him to make sure of getting in front of the ball. CHAPTER IX. THE LEFT-FIELDER. The simplest of the three out-field positions is the left-field, and one evidence of this is seen by the fact that a left-fielder almost invariably leads in the averages. If fielding were the only consideration, the man who was the surest catch, who could run the fastest and throw the longest, would be the best man for the left-field position; but other points enter into the question. A team, to win, must have hitters as well as fielders, and it is therefore usual to fill up the outfield with good batters, even at the expense of a slight weakness in fielding.