Occasionally you will need to catch a ball that has been fielded by the catcher. This could be on a bunt out in front of the base or a dropped third strike. After fielding the ball close to the first base line, the catcher will need to move to one side of the foul line or the other to make sure his throw will not hit the runner. You will need to position yourself the same side of the foul line that the catcher is on. If he is in foul territory, step across the base well before the runner gets there and use your right foot to touch first. If the catcher is in fair territory, use your left foot to contact the bag. Always give the first base to the runner.
If you field the ball and have time to beat the runner to first, you should. This is a much safer play than throwing it to the pitcher covering the bag.
There are times when you won't be able to beat the runner to the bag and will have to throw the ball to the pitcher. Sometimes you will be able to underhand the ball and sometimes you will have to throw it. Either way it is important to remember:
A left-handed first baseman has a real advantage in starting a double play. When fielding a ground ball he is already lined up for the throw to second, where the right-handed first baseman must turn to make the throw.
There are two ways to make this play.
1. The first is for any ball hit to your right. On this play, you will field the ball, make the throw to the inside part of second base if you were holding the runner on or to the outside part of second if you were playing behind. After making the thrown hustle back to first for the return throw.
On any ball hit to the right of the first baseman, you may want to have the pitcher always cover first. This way your first baseman can focus on fielding the ball and making a good throw to second. It's also good training for the pitcher to get used to covering first on that play.
2. The second is for any ball hit to your left. On this play you are so close to first base that you can field the ball, touch first base for the out and then make the throw to second. Make sure you call out "tag" as you make the throw to second. This lets the shortstop know that he must tag the runner to complete the double play.
On this play the runner will be farther down the base line. Make sure you step inside or outside the baseline after you touch the bag to make the throw. This will give you a clear path to throw the ball to second base. If you step inside then throw the ball to the inside of second. If you step outside throw the ball to the outside of second. The shortstop will see which side you're on and position himself towards that side of the bag.