Anyhow, you mentioned hitting the ball within the effective strike zone already, so I understand that. However, can you elaborate on waiting for the ball, being in position, and impacting the ball earlier when I'm not attacking? Do you mean that I have to wait for the ball once I move in the right position to hit the ball? For impacting the ball earlier, what does this exactly mean? Impact earlier on blocks/pushes? I'm not so sure what you meant here.
Waiting for the ball...
Many players are in a rush to hit the ball early, often they impact the ball too far in front of them. They do not allow the ball to come into the strike zone. If you are in position, then you are waiting for the ball to come into the zone. If you want to hit the ball while it is higher, then you should have positioned yourself a little more forward closer to table.
It is NOT a sin to allow the ball to drop some (preferred on underspin balls, frowned upon by coaches vs incoming topspin balls) it is better to let it drop a little and impact the ball inside your effective hitting zone and still make a strong and spinny shot then to try to hit it too early, too far in front that saps power, spin and consistency.
This one point here is a stumbling stone for many players. they are told over and over to hit ball early while high, but it is all at the expense of good position and hitting it in your zone.
An example would be a step around FH finishing shot. You do the step around and hit it too far in front, you lose all kind of power, spin, and accuracy. You miss more than you should, your landing percentage is not super high. You do the same step around and let the ball come into your strike zone... even if the ball is net high or even below the net (sometimes even table level)... you hit that ball in the zone with your 70-80% power loop, that ball is gunna land time after time with good pace and spin.
Kim Jung Hoon talks about it n his TAK9.com vids that Nexy puts up on their site. KJH is always talking about a feeling of "Catching" the ball on impact. That is a good way to think about it.
Impact earlier when not attacking... that means that if you decide to NOT attack, (make a an underspin push shot) you should step in and make your underspin shot right after the bounce on your side.
When you wait forever to think about attacking and bail out, or you already decided to not attack and want to push it while it is higher or falling downward... you give opponent a LOT of time to see you are not attacking. You also give the opponent more distance to read the ball you give him, he has more time to step around and B-slap that sucker by you if he chooses. You also lose possible angles to at least make him move. You also have a more difficult time controlling the ball.
When you take the ball early on your underspin shot, you have a lot of benefits. Best one is you take away time from your opponent. Nexy is control, it is much better of bounce. if you stepped in over the table, then you are looking over the ball and see it better, so you read it better. Since you are in position on balance with that step in footwork, you can make good use of deception with sudden open or closed wrist right before impact to apply more pressure or outright win the point, you also have more angles, so you make opponent move (and hopefully make an error or chicken out on attacking), you can more easily make heavier spin with a shorter stroke, so that makes it harder to read. You might also get some errors from that heavy push you made with that short stroke.
You see now what I was saying in impacting the ball earlier if you decide not to attack.
Blocking... Stepping in (or to the spot) and blocking the ball right off the bounce has the very same advantages. Your control and consistency go WAY up and apply the same pressure on opponent. You can also change grip pressure (soft had) to "Kill" the spin of your opponent's loop. Many Korean J-Pen players do this well with their traditional J-Pen BH block. You can also turn the block into offense with a tiny bump through the ball at impact (active block) since you are looking over ball in position.