Hi, thanks for considering to read this post. [everything I mention hereon is from your perspective, ie., imagine you are hitting the ball and you are right handed] OK, so I can hit a twist serve no problem but my question is, how exactly is this kind of a serve possible? It curves to the left before jumping up to the right. Which means, the direction of the spin on the ball is different to the direction that the ball was travelling. Before I move on I'd like to mention the 'inside out' slice backhand, a shot that Federer often uses down the line- it initially looks like it is going right, but then curves to the left. From what I understand this is done by letting the hitting side of the stringbed of the racquet face the left, and with this you are able to hit the right hand side of the ball. Your swing will be an emphasised left to right, up to down swing, which I believe, produces friction making the ball travel to the right. The spin on the ball is going from left to right, which eventually makes the ball curve to the left. So in order to hit a ball that travels in a different direction to the direction of the spin on the ball, you have to use friction.. or something like that. The ball will tend to go in the direction of where the racquet face is facing, but if you swing through in the other direction it will create friction and yeah... I feel really uncomfortable using these physics terminology but anyway, that's what I think. SO, if this is true, how does this occur in a twist serve? We've all heard of the instructions on how to hit the ball (clockface, from 7 o'clock brush to 1 o'clock, etc.) but what exactly is happening? Let's say I hit a twist serve from the Ad court that lands in the backhand corner of the opponent's service box, and after the bounce it jumps distinctly to the right. All right, you're going to hate me for asking these questions... Q1) Which part of the ball did I hit? Here is the ball: O Where did I hit? Often people say 'hit the bottom left', but this isn't possible unless the racquet face was open, or facing upwards. Which leads to the next 2 questions: Q2) In what position was the racquet on contact with the ball? What I mean by that is, was the racquet standing up (like you see on display at the shops), or was it tilted, horizontal? Q3) Where was the racquet face facing on contact? Was it facing to the left, square to the net, to the right? Up, down, forwards? Q4) What would the swing direction look like if you looked at it from directly above me? I know that many of you would think "I don't know what exactly is happening, but I don't worry about it and just do it". But sometimes it's better to understand what's happening. For instance, I have a Video cassette player. I didn't know how it worked and I didn't know what was happening inside, but I could watch videos so it was ok and I didn't have to worry about it. But one day it broke and the cassette got jammed. What did I do? Well, I could've taken it to a reparist, but instead I tried to check out what was happening inside by myself and I was able to fix it. OK that was a stupid story and I admit it but anyway the bottom line is: If I know what exactly is happening when I hit a twist serve I'd know how to improve it and repair any problems I encounter. So please, help!