The opening lines to my book, Table Tennis Tactics for Thinkers, is, "Tactics isn't about finding complex strategies to defeat an opponent. Tactics is about sifting through all the zillions of possible tactics and finding a few simple ones that work."
But how do you find these simple tactics that work? Simple - by watching the opponent before you play; asking others who have played or watched him play; and by experimenting during the match. Generally, you want to find perhaps two or three tactics that work very well, typically one on serving, one on receiving, and one in rallies. Maybe you can even handle four!
I'm going to use my own game as an example of how to go about finding a few simple tactics that work. (Keep in mind that I'm talking about my game back when I was in training!)
Any experienced player watching me play would note that receive was a strength, especially against short serves, where I can flip or push short well, along with occasional long pushes. But if you tried serving long too much to avoid my receive against short serves, I'd attack it pretty well. In fact, on paper, I was good against nearly all serves! However - and here's the BIG however - I was not against lots of variation. And so a good coach might tell his player, "Throw all your serves against him, even your weaker ones, keep varying them and he'll never get comfortable."
On my serve, the first thing anyone would notice is that I essentially follow every serve up with a forehand attack. So why make it easy for me? Make me move by receiving at wide angles. Since I'm trying to cover the whole table with my forehand on that first shot, I often jump the gun if I think I see where the receive is going - so if you aim one way but change directions at the last second, I often get caught. If you receive to my backhand, I get to step around and forehand attack, and I'm in position to follow with a second forehand. But if you receive to my wide forehand, I get one forehand and then you can come back to my backhand. Also, I'm a rhythm player - I'm better against a good predictable receive than a weaker but less predictable one. In other words, you may make a good flip or a good push and I may still attack it with my forehand, but if you vary the two, even with lower-level flips and pushes, I lose that rhythm. And so a good coach would tell his player, "Constantly vary your receive, make sure your long receives go to wide angles, often to the forehand, and try faking one way, and going the other."
In rallies, those watching would note that I'm stronger on the forehand side, but that my backhand is super consistent, and I have no trouble dealing with strong attacks on either side. If you try to overpower me backhand-to-backhand, I'm probably going to win unless you have a really nice backhand smash. However, I don't have much of a backhand attack, and don't backhand attack down the line very well. And so if you attack my wide backhand and middle, you'll get a lot of consistent but relatively soft returns that you can put away with your forehand, assuming your forehand is your better put-away shot. Or you can go to my forehand to draw me out of position (pick that shot carefully since I'm going to attack it!), then go back to my backhand and get an even weaker backhand return to attack. And so a good coach would tell his player, "Attack his middle and wide backhand, and look to end the point with your forehand. Look for chances to go to his wide forehand and then back to his backhand."
So here's what the coach might say to his player before he plays me, either before the match (if he knows my game) or between games:
"Throw all your serves against him, even your weaker ones, keep varying them and he'll never get comfortable. Constantly vary your receive, make sure your long receives go to wide angles, often to the forehand, and try faking one way, and going the other. In rallies, attack his middle and wide backhand, and look to end the point with your forehand. Look for chances to go to his wide forehand and then back to his backhand."
I timed it, and speaking slowly, that took me 25 seconds to say. And yet, many experienced coaches might say that's too much to remember, perhaps one thing too many and too complex. It all depends on the player. So here's a simpler, slightly shorter version that probably would work better, and took me 17 seconds to say:
"Throw every serve you have at him, and he'll never get comfortable. Throw every receive you have at him, but make sure to go to wide angles, often to the forehand, and maybe fake one way, go the other. In rallies, attack his middle and backhand, or go to his forehand and back to his backhand, and look for chances to end the point with your forehand."
But if you ever do play me, ask me how to play me and I'll fill your head with fifty different things to do, and you'll be so confused I'll eat you alive!