When and how much to vary serves?

I think instead of directly answering the question I think I would approach this by opening up the parameters of the question. So lets ask a broader question that includes original poster's question and by talking about the broader question we can indirectly 'maybe' somehow give a good insight on the original question.

So the broader question is what is TT?

Many people can answer it in many ways, but for me my thoughts on TT is that it is a sport that incorporates a lot of strategy. Having an awesome serve, bh loop, receive, etc can go long ways, but also reading the opponent and thinking steps ahead of the opponent can be crucial. I think that as a beginner one tries to just perfect each swing and learn each component of the game, the intermediate has all the basic components and are capable of having an identity, but i think with any sports the leap from intermediate to expert (or even pro) is the mental (and emotional) game. [but not to stray we will not discuss the emotion part]

If you are playing chess while your opponent is playing checkers, even if that person might be superior athletically, there are ways you can win. If you see zjk, ma long, xuxin, they are all athletically gifted, superb in each stroke, and all are emotionally strong, but to be the top you need to bring good strategy, know your strengths and weaknesses and know your opponents strengths and weaknesses. Employ a strategy that lets you use your strength while hiding your weakness and exploiting your opponents weakness and avoiding their strengths. 

This means for me during the first game (hopefully) i use various array of serves to assess (assuming this is the first time i am playing my opponent, with a well known opponent i don't need to do this) their strength and weaknesses and their receiving patterns. I also look if they play the mind game as well, say if i give them a bh short down the line serve do they receive it the same way every time or do they change it up? Do they give me the same receive twice and the third one pretend to give it the same way and then change it up? What serves gives them trouble? Can they read the spin by not looking at my racket angle and just by how the ball bounces and quickly react? etc etc etc...

Say your opponent can read the spin by just seeing the ball (most good players can do this through lots of experience) then really the variation of your serve is not as important (if it is not perfect i guess), even if your serves are identical and give off different spins. If your opponent cannot do this, then yes you must exploit this, but if he can then you need to think about third ball, fifth ball, etc.. How if i give this serve where does it usually land on my side and how am i going to attack or set up for the next return. 

You have to find out if your opponent is adept at flicks or strongly returning a fast topspin serve. So even if your backspin to the bh down the line short serve is awesome, if he can flick it and put you in a precarious situation you need to not give him that serve, same thing with a fast topspin serve. But if you have a serve that your opponent has trouble with, that is what you want to exploit. You need to give that person that serve more often than other serves but not so much where he/she will get use to or comfortable with. 

So for me (as an example) my best serve is a fast sidespin pendulum serve deep to the opponents corner, i have a lot of versions, but i have the same serve that is a bit high and one that is low. If my opponent has trouble with it the first time, i give it to them a second time, if they adjust really good then whatever, but lets assume they have trouble with it again, that is where the chess playing comes in. 

So then i look the next time i am serving, are they looking for the same serve and adjusting for it? (for example if he is a right handed player is he/she moving a little more towards the right and a step back to have more time to bh loop it?) say that opponent is doing that, adjusting like that, that is when i probably will give a low sidespin fast serve to the fh corner or short down the line fh backspin or no spin serve. This keeps my opponent from adjusting (or cheating) to receive my fast sidespin long serve. Then i can give him a short sidespin to his bh serve, (sort of the he shi wen serve that serves to the side).. or give him the same long sidespin serve that is a bit high, making him uncomfortable in his receive and not letting him do what he wanted to do the next time he saw a low long sidespin serve to the corner..etc etc.. in other words I make him keep guessing and put him on edge of what might my next serve is. I also like to take a breath,(most ppl just serve right away.. i say don't do that! take a few seconds, set a plan for each point) look where the person is located and see, is he a little bit close to the table? fast long serve. is he a little far away? short backspin.. etc etc.. obviously most good players will receive these serves, but you want is a. not let them attack you immediately, b. try to position yourself for an advantageous situation c. maybe get a pop up or a whiff ^^

But if he receives all the serves flawlessly then you really need to think about 3rd, 5th ball etc.. 

If i serve a short bh backspin ball people 70% return it to my backhand side with a flick or push and if bh looping or bh rallys are your thing you probably will want to serve it to him in that way that is with the assumption that his bh is weaker than yours. If his bh is stronger than yours, well that would be stupid, no matter how great your bh is. So you need to keep in mind that you want to facilitate your strengths and you can make it happen more often than not when you are serving. Obviously, if your opponents fh and bh is stronger than yours then you probably already lost even before playing the game ^^

Anyways so i know this is incredibly long and confusing, but what i suggest is you get one serve that are you are really great at and variate from that one serve. So for example, my long sidespin serve (and really for this to be a really good serve it has to be very fast, lots of spin, hitting the exact corner and be low) now i can have a short sidespin serve to the bh. a short and long sidespin to the fh, short and long to the mid. with that you already have 6 serves. now you can incorporate backspin with sidespin or just pure backspin. that means you have now 18 serves. then you have the no spin, 23 variations for one serve. For all of these serves to be effective you need your spin, speed, placement, and almost no difference in the stroke. in other words lots of practice.. 

if you get good with those then you try a reverse pendulum serve like zjk and that has insane amount of options and variations.. ( i think there is a reason all the top players have this serve, super effective if it is good).. and i also have a tomahawk serve sequence, to change up the game if i am in trouble or i am in a game point situation with a comfortable lead to mess with my opponent..

anyways.. i hope this helps.. its late and now i am just rambling.. i might have to look at this post and revise.. but i hope this shows you how you should think in playing tt and how you should think when serving and playing each point. Cheers

@illinichamps thanks for your detailed reply! I think I get where you're coming from, I've seen posts about how your serve can dictate the angles of play e.g. use of placement and sidespin, but tbh I don't think that far ahead like you do in terms of 3rd ball, 5th ball etc. I also don't look to see if my opponent adjusts before my serve or mid serve, which definitely are things I'll try to do from now on

@kenneyy88 I'll definitely think about what patterns of play I like - still developing my style. I have a quick q tho, how can you tell between an opponent reading your serve correctly but miss hitting, and them miss-reading the serve and popping it up/long?

Oh, and if I find I have a 'killer' serve against a player, should I use it as often as I can to get lots of points (but run the risk of them reading my serve), or save it for crucial points in the game like 9-9 or 10-10 when I really need an easy point?

Thanks! 

 Yep.

Mine for example are:

Short Heavy backspin (and then variation in placement and amount of backspin of course)

Tomahawk (side or underspin / side)

Pendulum (side , side/topspin)

Those are the 3 I am very comfortable executing and know that against ANY player - no matter the level, they are going to keep me having a slight advantage in the point (normally a predictable 3rd ball - of course of varying difficulty according to the opponent's strength)

Then I have some tricky ones:

1) the float (short no spin made to look like underspin) - hoping for a pop up but might get flicked (ie. less predictable 3rd ball)

2) the fast topspin serve down the line or to the extreme BH (depending where and if the opponent is standing slightly off balance)

3) LONG HEAVY Underspin serves against players who suffer when looping very heavy underspin.

Obviously I use the 3 main serves most - then out of the tricky serves I'd use no.1 around once per set, number 2 if my opponent stands incorrectly, number 3 if I feel my opponent has been struggling with the short underspin - I'd test the long underspin.

As to variation, I normally change serve each time, not allowing my opponent to catch on - but if he dumps a particular serve into the net, or out - I sometimes repeat it, especially if I can see he is flustered. 

Generally, I start the set SAFE with short underspin - in the beginning I really want predictable returns where I can use the 3rd ball and get into the game well.

I then use pendulum and Tomahawk serves to break up the short underspin routine and vary the points - for example the best reply vs a pendulum sidespin is to attack it (normally drive is safest - using my own spin against me, but some players even add their own spin) - so when I execute this serve I take 1/2 a step back right after and get ready for a fast return which I aim to loop back (counterattack) or if it is too fast, I use an active / aggressive block. 

This way I change also the tempo of the game...

Then as the set is towards the middle, I select a tricky one (or max 2) depending on the situation and opponent... 

towards the end, I play safe generally the short Underspin.

You consistently have a way of messing up the "quote" function - not sure the cause but I fixed it in this post...

Brian Pace's Serve and Serve Return video has strengths and weaknesses and I have summarized them elsewhere and should/could do a full review sometime.  What you say is true - he has some good thoughts about who the proper "customer" for a serve is and what kinds of returns are reasonable to expect.  For overall serve strategy and deception, not so much.  I think that my serves are at a level now that I will get much more out of it than I did when I first watched it.