Team defense starts with attitude - every player MUST want to play defense in order to be successful as a team defense?
Confidence and aggressively attacking the ball
Movement and verbal communication are also necessary
EVERY player on the field moves and is involved and performing a task on EVERY play
the team needs to know the game situation
Team Defense Basics:
1. ALWAYS want and anticipate that every ball will be hit to you
2. ALWAYS be in the proper ready position
3. Know what you will do with the ball BEFORE it is hit to you
4. ALWAYS play the ball; don't let it play you
5. Know the field, wind, and sun conditions
6. Know who should be covering a base and remind each other
7. Watch the ball and catch it FIRST
8. Know your pitcher's ability and pitches
9. Know and study your opponents at bat
10. Be aware of priorities in fly balls
Do not throw the ball unless necessary; every time the ball is thrown there is a chance for an error
The infield should ONLY be pulled in when a run cannot be given up

extension:

Fielding

Backing Up the Play. Almost every time an outfielder makes a play, another outfielder is backing up the play by moving behind him. If the ball gets by the initial fielder, the other fielder is there to keep the ball from rolling all the way to the wall and allowing the runners to take extra bases. Infielders also back up plays when they have time to react, and the catcher often backs up plays at first base, protecting against errant throws by an infielder.
Calling Off Other Players. When the ball is hit in the air, the fielder who expects to make the catch communicates this by calling off other players. On pop-ups or fly balls, the player with the best chance to catch the ball calls out “mine” or “I have it,” and everyone else backs off. In the outfield, the center fielder is generally the best fielder and is in charge of defensive play. Thus, if he has a good chance to catch the ball, he will call off the other fielders and make the catch himself. If you see fielders collide on a fly ball, it is probably because someone did not make a call, or the fielders did not hear each other.
Hitting the Cutoff Man. When the ball is hit deep into the outfield, either for an out or a base hit, and a runner tries to advance, the player who fields the ball may opt for hitting the cutoff man. The cutoff man is an infielder who stations himself between the outfielder and the base the throw is going to. The cutoff man's job is to catch the long throw from the outfielder and make a shorter throw to a base. The cutoff man also catches any throws that are off target and relays them to a base. If necessary, he can cut the ball off to keep the runners from taking an extra base on a long throw.
Guarding the Lines. Fielders who are guarding the lines have moved closer to the foul lines in the infield, the outfield, or both. The purpose is to make it less likely that a batter will hit the ball fair down the line. Fielders usually start to guard the lines when the score is close in about the seventh inning, because a ball hit down the line often results in a damaging extra-base hit. The disadvantage of guarding the lines is that it opens up the middle of the field, making it easier for the batter to hit a single to that part of the field.
Infield in. The manager brings the infield in by having them station themselves closer to home plate than they normally would. They do this when a runner is on third, and they want to prevent him from scoring on a ground ball. Because they are closer to the batter, however, the infielders have less time to react when the ball is hit. This means that the batter has a better chance of knocking the ball through the infield. Like many strategic maneuvers in baseball, bringing the infield in is a calculated risk, with the fielders gambling that the ball will be hit to them and the run will be prevented.
Infield at Double Play Depth. When the infield is at double play depth, the first and third basemen stay in their normal location, but the shortstop and second basemen move closer to second base and a couple of steps closer to home plate. If a ground ball is hit within their range, this positioning makes it easier for them to turn a double play and make two outs.

First Base

Desirable Characteristics:

1. should be tall and agile
2. should have quick hands and feet
3. preferable if left handed making it easier to field bunts and throw to third base
4. should be able to hit with some power

You must ALWAYS play close enough to the base to be able to take the throw
Straddle the base with your feet while waiting for the throw
if the throw is on line, stretch out and catch it
if the throw is on the home plate side of first, put your right foot on the bag and stretch with your left
if the throw is on the outfield side of first, put your left foot on the base and stretch with your right foot
When throwing to the pitcher covering first, throw shoulder high at least two steps before the base; throw it, don't toss it unless you are very close; you can throw more accurately than tossing
When holding a runner on base, put your pivot foot on the base and the other foot shoulder width apart towards the pitcher
Pop off of the base and cover your position or you will create a large hole in the infield
Charge hard on bunts
Let EVERYONE know if the runner is stealing; be loud
You are responsible for taking relay throws to home on hits to center and right fields
On a dropped third strike that goes to the screen, clear yourself for the throw from the catcher to the outside of the baseline
Back-up throws to second base from the left and center fields
In a close game, guard the line in later innings

Second Base

Desirable Characteristics:
1. must have quick hands and feet
2. need the ability to get rid of the ball quickly
3. must be able to make the pivot on a double play
4. most throws will be short so a strong arm is not necessary

You must be quick on your feet to hold the runner on, cover first base, and to field your position
On a hit to the right side of the outfield, go out towards the ball for the relay
catch the throw in position to throw out the runner
listen for which base to relay the throw to
if there is no play, run the ball back into the infield

On a hit to the left side of the outfield, cover second for the relay throw
You will usually hold the runner on second base with a right handed hitter up to bat; you may have the shortstop hold the runner if the pitcher overpowers the hitter
With a runner on first base and the hitter bunts, cover first base
With a runner on first and second base and the hitter bunts, you may cover first or second, depending on the play called and the situation
You are responsible for covering second base on a steal with a right handed hitter up
On relay throws, the first throw from the outfield is the long one and the second throw by the infielder is the accurate one
Communicate with the pitcher, catcher, and shortstop on who has the base on a steal or hit back to the pitcher
Anticipate an overthrow by the catcher on the throw back to the pitcher
On pop-ups behind first base, you have a better angle than the first baseman
Double Play:
the most important play in baseball
cannot make the double play unless infielders heat or hade the bag?
a good rule of thumb is for the shortstop and second baseman to move three steps (8-10 feet) toward the hitter and two steps (5-8 feet) closer to second base
the player who is the pivot of the double play MUST get to the base as quickly as possible
be SURE to get the first out

Third Base

Desirable Characteristics:
1. must have quick reactions and a good pair of hands
2. must have strong arm
3. must be quick in your first three or four steps (90% of the ground balls fielded will be within the range of 3 or 4 steps)

With a runner on first and the hitter bunts, charge hard for the bunt
In a close game, guard the line in later innings
With a runner in scoring position and there is a base hit to left field, get into position for the relay throw to the plate
On a ball hit to right field, back-up the throw to second base
Go after any ball hit to the left side of the infield; if you can cut it off from the shortstop, you have a shorter throw

Infield

Your wrists must be loose and flexible ("soft hands")
Your palms should face the ball as it approaches
Play the ball in front of you; your hands should be well out from your body and as the ball contacts the glove, draw your hands in ("soft hands")
Keep your glove to the ground; you can come up much more quickly than you can get your hands back down on a scooting grounder
Fly balls that can be caught by an infielder or an outfielder should be taken by the outfielder because they are coming toward the ball
Pop-ups behind third base should be taken by the shortstop and pop-ups behind first base should be taken by the second baseman
The pitcher should never have to field a pop-up if an infielder can get to the ball

What Infielders Must Know:
1. Knowledge of the hitter
should know the type of hitter at the plate - pull hitter, opposite field hitter, spray hitter, power hitter, etc.
speed; is the hitter a fast, average, or slow runner?
2. Knowledge of the playing conditions
should survey the ground conditions around your position - hard, soft, fast, slow, wet, dry, wind, sun? etc.
3. Anticipating the play
aware of the game situation, number of outs, pitch the pitcher is going to throw

Tips for Infielders:
1. Think Ahead
2. Look for the ball to be hit to you on EVERY play
3. Have a comfortable stance, well balanced, and squarely facing the hitter
4. Have your body under control as you approach the ball
5. ALWAYS get at least one out on a ground ball
6. DON'T make unnecessary throws

Outfield

The Basic Four Qualifications:

1. Concentration
must focus on the pitcher and the hitter
the ability to react and good reaction time are a direct result of TOTAL concentration

2. Speed
the ability to get to the ball quickly is essential
centerfield is usually the place for the quickest outfielder to cut off shots to the gaps

3. Strong Throwing Arm
ability to throw long and accurately

4. Knowledge of the Situation
What? = What is the score?
Where? = Where are the runners?
When? = When and how to charge the ball
How?
The drop step is an essential skill for good movement by an outfielder
Most successful outfielders hustle EVERY moment they are on the field, they back-up EVERY throw and hit, and they throw to the right base at the right time
Outfielders need very strong, accurate throwing arms, especially the right fielder
The center fielder must be fast on his feet because he covers the most area
The right fielder backs up first base on all plays and second base on throws from the left side of the infield and outfield
The center fielder backs up throws from anywhere on the infield
The left fielder backs up third base on throws from the right side of the infield and outfield
Pay attention to the hitter's strengths and tendencies
Catch fly ballsa in throwing position while moving toward the target of your throw
ALWAYS use two hands
When a ball is obviously over your head, don't backpedal; turn and run
Hit the relay man head high with the throws
ALWAYS throw one base ahead of the runner
A one hop throw is better than a throw over somebody's head
NEVER hold a fielded ball; get it into the infield immediately
The first throw of a relay will be the long one

Right Of Way Rules:
1. the centerfielder takes anything he can reach
2. all outfielders have priority over infielders
3. outfielders should call loudly and continually until they make the catch
4. wait until you are sure you can catch the fly ball before calling it

The center fielder is the captain of the outfield; if he can get it, he calls left or right off
On a lopper over the infield, the outfield should catch it because they have a better throwing angle
You must concentrate on every pitch and anticipate plays
NEVER run with the glove hand extended; turn and run at top speed to the spot where you think the ball will come down; then turn and make the catch or extend the arms at the proper time