Where do they Play?
The third baseman has a long throw to first. If they are playing behind the baseline the throw not only has to be strong and accurate but quick. Only hard hit balls will be routine plays. Also, a bunt down the line doesn’t have to be a very good one to be a hit. Therefore, I always play the third baseman one step in front of the baseline. I would much rather prevent a bunt toward third than try to field one. When the batter is in a bunting situation, I play the third baseman in a step or two further.
The third baseman should play about three or four steps off the line when there is no runner at third. Far more hits will go to the third baseman’s left than down the line. Also, the difference between a single and a double is not that great due to the ease of stealing second. Only if there are runners at both first and second will I bring the third baseman over to within two steps of the line.
Responsibilities
The third baseman is responsible for covering third if he cannot get the ball. Since they play closer to home plate than the shortstop, they can aggressively go to their left after ground balls without fear of running into the shortstop. The third baseman has priority over the pitcher in fielding bunts and slow rollers since their momentum is not taking them away from first. The third baseman should align the shortstop as a cutoff man for outfield throws to third. The third baseman should signal the right handed pitcher when the runner at first has too big a lead or is running to second without waiting for the pitch. The third baseman should hold the runner on at third so the pitcher can make pick-off throws there. The third baseman should provide a good target for the catcher on pick-off throws to third by the catcher. This means not standing on the baseline but rather to one side near the base. The third baseman should not touch third base except on a force play there.
Ground Balls
The third baseman has time to pick up a fumbled grounder and still make the play at first. This means always using the bare hand to pick up the ball. The third baseman should always set the feet before making the long throw to first. A wild throw by the third baseman is one of the worst errors an infielder can make since the ball often ends up in the right field corner.
Picking up a slow roller as in a bunt or hit off the bat handle is one of the third baseman’s most important skills. This must be done with the bare hand. The glove should be there as well but it serves merely as a flat surface against which the ball is pressed by the bare hand while getting a good grip.
The only time the ball is thrown without standing upright and throwing overhand is when tossing the ball to the catcher on a play at the plate. This play is made from the ground with no backswing of the throwing arm. The third baseman must practice this toss being careful to finish the toss with the finger pointing at the target. Pointing at the target keeps the toss from being too high. Following through on an underhand toss tends to make the ball go over the intended target.
Covering Third
Most third basemen want to touch the base while waiting for the throw at third. They should not touch the base unless the play is a force out and the throw is online. Having a foot back on the base makes catching the ball more difficult and makes taging the runner harder. With one foot back the third baseman is not mobile but anchored. The third baseman with a foot on the base risks having the foot stepped on by the runner.
When there is a runner at second, the third baseman should assume their normal fielding position. When the pitch strikes the catcher, (hopefully in the mitt), and not before, the third baseman should move to the base and assume the base covering position for a throw from the catcher. At no time should the third baseman look at the runner. They should look only at the ball. The position for covering third for a throw from the catcher and the runner coming from second is one step down the line toward second, on the home plate side of the baseline, with feet square to the catcher. This way the third baseman has maximum mobility for catching the throw and can make the tag on either side of their body. If the throw is online they can pivot on the right foot to block the baseline as they catch the throw.