Covering the Base
The second rule of defense is to cover a base. If the first baseman cannot get the ball they will usually be covering first base. In children’s baseball the throws are often inaccurate. This puts a premium on the mobility of the first baseman. If they have one foot solidly on the bag and one foot extended toward the player fielding the ground ball they are not at all mobile. They cannot even jump very well for a high throw. The first baseman should have both heels near the bag with the feet a little more than shoulder with apart (the universal “ready” position in almost all sports) facing the player that might throw the ball. They are now ready to catch the ball for a force out. NOTE: No fielder should set up touching the base while waiting for a throw.
If the throw is seen to be on line to the base, the first baseman can step toward the oncoming ball with either foot (one gets a couple inches more “stretch” toward the ball if the glove side foot goes toward the ball). The other foot is shifted to place the ball of the foot against the side of the base. If only the heel of the foot is on the base it can easily be pulled off the base in reaching for the ball as the foot pivots around the ball of the foot which is on the ground. If the ball of the foot is on the side of the base the the push toward the ball involved in the stretch will be pressure on the base.
Since both heels begin only an inch or two from the base the first baseman has no trouble “feeling” for the base while looking at the ball.
Because the first rule of defense is to get the ball the first baseman should not be reluctant to leave the base to catch a bad throw. As soon as it is obvious that the throw is off line, the first baseman should move parallel to the baseline to catch the ball. Crossing the baseline can cause a collision with the batter. If the ball is caught going toward home the runner may be close enough to be tagged. If the ball is caught going toward the outfield fence, the first baseman may be able to throw out the runner with a toss to the pitcher covering first base. (Yes the pitcher will not be there on a grounder to the left side but the runner would almost certainly beat the play anyway since there is less time on left side ground balls.) If the first baseman can get beyond the line of flight of the ball and catch it coming back to the bag he may be able to beat the runner.
When the runner must be tagged the technique for covering the base is quite different. The fielder should be a step down the baseline toward the runner and on the same side of the baseline as the ball. The first baseman’s feet should be just a little more than shoulder width apart, squared up (the same distance from the ball), and toes pointed at the ball. It is exactly the same stance one would use when expecting a batted ball only pointed at the fielder who will make the throw rather than at the batter.
The first baseman is a step down the line toward the runner because we do not know where the throw is going. This way the first baseman can make a tag on either side of their body. Which ever side the ball is on that is the side for the tag. If the ball is going right toward the first baseman’s body, they pivot on the left foot toward the baseline while the ball is in flight in order to block the base before applying the tag.
If the first baseman uses the regular major league or high school technique of holding the runner on first, they run a much greater risk of a wild throw or of catching the throw but being unable to apply the tag since the ball is on the wrong side of the base. The recommended position above also puts the first baseman a little closer to the pitcher and a step closer to his fielding position when the pitcher delivers a pitch home.
Using the Mitt
The first baseman is allowed to use a special glove which makes it easier to field throws with a long stretch and “scoop” up low throws. Most young players who play first base do not own such a glove. It might be worth the expense of buying a “team” first baseman’s glove if you will be coaching for several years. Playing with such a glove takes some getting used to. Since the webbing is so long the player who is used to an ordinary fielder’s glove will tend to catch the ball too close to the hand or over compensate and have the ball miss the glove completely. Have the first baseman use the glove in warming up and pay attention to where in the glove the ball strikes. After a few hundred catches the player can probably do just fine.
The mitt makes it relatively easy to “scoop” low throws out of the dirt. The psychological barrier to doing so is most of what has to be overcome. The first baseman will be afraid of a “bad hop” of the low throw coming up and hitting them in the face. They will tend to pull away from the ball which lifts the glove and lets the ball go under it.
Ideally the finger tips of the wide open glove (a really large target, perhaps the largest of any glove on the field) will be touching the ground with the glove perpendicular to the ground in the line of flight of the ball. If the ball hits the ground within 2-3 feet of the glove it will not be able to bounce above the glove and should be caught. If the ball will hit further away than that the first baseman will be able to react to the bounce by lifting the glove enough to make the catch. Naturally the first baseman will have cleared away any rocks that might cause a bad bounce before play began. (Actually the players will not do this on their own. You will have to nag them to get them to do it at all.)
Backing up a Base
The first baseman should back up home when it is obvious there will be no play at first. If there is time, the first baseman can replace the catcher at home since he has the better glove for catching a throw. Backing up the pitcher is especially important when there is a runner at third and the pitcher makes a wild pitch. The first baseman has to run as quickly as possible to get behind the pitcher covering home in case of a bad throw from the catcher. The other infielders must cover other bases and are unavailable for the task. Since it never hurts to back up the pitcher when the runner at third is the only runner, the first baseman should come in anyway just to keep the habit.
The first baseman can also back up second for throws from left field. This is really the job of the right fielder but at this age they often watch rather than playing baseball.
Positioning
With no one on base the first baseman should play rather deep. This would be 5-6 steps behind the baseline at least. Most first basemen are so worried about getting to the bag in time that they want to play right beside it all the time. By playing deep the first baseman has a much better chance of catching the pop fly down the line, one of the most common hits for players of this age. The first baseman also greatly extends their side to side range for ground balls. Since the throw to first is so short they can play quite deep and still have plenty of time to get the ball to the pitcher covering first.
If the first baseman thinks that they will not be able to get to first in time if they play that deep remind them that the batter has to go over 60 feet and they have to go only about 25 feet. Using runners from home during infield drills will also reassure them.
Right handed players can be a step further off the foul line than left handed first basemen. You will rarely want to move the first or third basemen laterally for a pull hitter or slow swinger. That adjustment is made with the middle infielders.
The first baseman should be coached to aggressively go after grounders. Otherwise they will turn routine infield outs into hits by running away from a ground ball they could catch in order to cover first.
With the first baseman playing so deep the pitcher should expect to field all bunts to the first base side. If the ball is bunted so hard toward first that the pitcher cannot get it the first baseman can pick it up and tag the runner or step on the base in plenty of time since the ball was bunted much too hard. Only a perfect bunt just out of reach of the pitcher and too far from first for the first baseman to get will be a hit. That is a very small risk given the bunting skills of players at this age.
When the pitcher or catcher fields a bunt, the first baseman should set up on the infield side of the bag to give the thrower a clear target unobstructed by the batter running to first. It is crucial in this case that the first baseman be mobile since missing the throw can put the batter on third.
Alert!
The first baseman must remain aware of other runners at all times. In one game I had three runners score from second on routine infield ground-outs because the first baseman did not pay attention to any runner except the batter. After every play at first the first baseman should come away from the bag with the ball in their bare hand ready to throw and looking for an unwary runner to throw out. To reinforce this habit infield drills should always involve a quick throw by the first baseman to some other base right after they catch the ball.