While not as flashy as topspin attacks and kills, few strokes are more important to your success as a player than the often under-appreciated block stroke.  The basic “control” block is one of the very first strokes that all players learn and then unfortunately, many players stop developing and improving this core technique. 
What exactly is a block stroke?  It is normally a short stroke played to control your opponent’s attack when you do not have time or position to execute a longer counter-attacking stroke.  Blocks can be active or passive, and can be played with or without spin.  It is possible, especially at the lower levels of play, to build a successful style of play around blocking.  Moreover, players at every level need to be able to execute one or more of the seven possible variations of this important stroke. 
There are two general categories that blocking strokes fall into, blocks produced without adding spin and blocks with spin added. 
Blocks Without Spin
1.The Control Block
As I mentioned above, this is often one of the first strokes a beginner learns.  The stroke is played early in the bounce (ascending stage).  There is little acceleration of the racket during the stroke and the feeling is one of “carrying” the ball.  The hand is firm during the stroke and the goals for this stroke are to control your opponent’s speed, and to place your return into a difficult position for the opponent.  Your racket angle will be closed as much as needed to control the amount of topspin from your opponent.  The control block is often the primary block for many different styles of play.
2.The Drop Shot Block
This blocking stroke is very similar to the control block.  The ball is contacted in the ascending stage, but this time with a relaxed grip.  At impact, you want to feel like you are absorbing the speed of the ball and you may even move the hand slightly backwards at impact to help with this.  This will require an “active” hand at contact and your racket angle will depend on the amount of spin on the ball.  This block is often used by attacking players to disrupt the opponent’s timing and also to force the opponent to move forward.  Many players use this block against mid-distance topspin players who often have problems moving forward for short balls.  Long-pips blockers who want to produce a block that will bounce very short to stop their opponent’s continuous topspin attacks will find this stroke very effective.
3.The Active Block
The best way to think of this stroke is as a “smash-block”.  Unlike the smooth stroke (carry) of the control block, this stroke uses “smash” touch with maximum acceleration achieved at contact with the ball.  Imagine you are driving a nail when contacting the ball for the active block.  Contact should be made at the top of the bounce with a firm grip and both the wrist and the forearm are used for this stroke.  The purpose of this stroke is to score the point or to push your opponent back from the table.  The active block is often used against slower and higher opening topspins.
4.Control at Far Distance Block
This is an emergency stroke played away from the table with the purpose to gaining time for your next stroke, and just to make a safe return of a powerful attacking stroke.  This block is executed as the ball is descending with a controlled advance of the racket (carry touch).  This stroke needs to be well placed as it will have little speed or spin.  This type of block is most used by mid-distance players to “fish” the ball back on the table.
Blocks With Spin
5.The Backspin Block
Sometimes called a “chop-block”, this stroke is very popular with long pips or anti-blockers as the slower speed and lower friction of these materials makes the stroke easier to play.  The ball is played in the ascending stage with a closed blade (inverted rubbers) or a more open blade for long pips rubbers.  There is “negative” acceleration at contact and the racket moved downwards and around the ball (like peeling an orange). This requires a loose grip and a very active hand at contact with the ball.  The purpose of this block is to make your opponent play the ball into the net or to disrupt his timing and force an error.  While the backspin block is a staple for long pips styles of play, it can also be very effective for attacking styles of play when mixed in with more aggressive blocks.
 
 
6.The Topspin Block
In recent years, this block stroke has become increasingly popular because it blends so well with the dominant modern style of counter looping.  The best way to think of this stroke is as if you are dealing cards.  This stroke requires a very active and relaxed hand with contact made in the ascending stage of the bounce with a closed racket.  You will feel the ball sink deep into the sponge as your racket is moving through the ball’s center of gravity with a closed racket (gumming touch).  The acceleration for this stroke occurs before impact and the axis of rotation is your wrist, not your forearm.  If you rotate your wrist and your forearm, then you are no longer executing a topspin block, but actually producing the full counter-topspin stroke.  The Topspin Block is mostly used to create “time-pressure” for your opponent.
7.The Lateral Block
This stroke is also called a side-spin block.  Contact for this stroke is in the ascending stage and your wrist will be either broken or extended to contact behind the ball with your racket, then moving to the right or the left side of the ball.  You will be touching the ball with spin touch and the acceleration of the racket will happen just before contact and come from your hand.  The purpose of this block is to direct your opponent’s return or to force your opponent to move a greater distance.   Lateral Blocks have been used by almost every style of play and are the primary backhand returns for the classic (one-side) penholder attacking style.
As we have seen, there are seven common variations of the blocking stroke.  Whatever your style of play, I suggest that you learn at least two or three variations that seem to best fit into your game.  Remember to practice mixing your block variations together so you can mix them at will to set “traps” for your opponents and force errors from them.
The Block Stroke may not be the most glamorous stroke in the game, but strong block strokes can take you a very long way in our sport.  Just ask our many time US Women’s Champion, Gao Jun!