Question on Biomechanics of the FH Loop

[NextLevel]

Coaching people who can't generate racket head speed is one of the hardest things you can do in table tennis.

 

[CroneOne]

There are a lot of examples her of heavy backspin from choppers. FH strokes against these will be quite vertical. When talking about backspin pushes and starting up the loop against them, this video really opened up my eyes...

I was amazed at how ML treated this almost like a topspin ball. You can see all of the rotation in his torso and his forward momentum. I had always thought that you had to lift pushes, but the truth is that if you can get the bat speed going very fast, you can really go through these pushes with a fast loop. Of course this is ML but when I put a few hours on the robot, I could start getting a few of these on. Then after trying these in games over and over, the confidence goes up to try and put some serious pressure on a BS push.

This Coach Li video has a lot of what you are talking about - he tends to lean right to left on the follow through. It could be just his demonstrating style though.

 

[izra]

does he really treat it almost like a topspin ball? the body turn is certainly there, but the bat goes from under his knee level all the way above his head. at the same time it doesn't seem to drift too far back on the backswing nor does it finish too much in front of him. i'd say there is quite a lot of upward motion from the arm there, but it is combined with a powerful forward momentum from the body turn.

if he were to hit a topspin ball at that distance from the table at the same angle, i assure you it would fly off the table.

 

[Boogar]

OH this video just reminded me of another way to make use of the body rotation in a more upward stroke!

Drop your shoulder and lean a bit over your right knee and then go up while turning the torso!

Very NICE! Now I need to delay my date tomorrow and go training!

 

[izra]

i've noticed a lot of people (my self included) try to use the body by leaning into the shot, as in follow the shot with both shoulders. this is not good, the result is much better if you follow the ball with the playing shoulder and move the other shoulder back as this way your body gets a turning motion.

 

[CroneOne]

does he really treat it almost like a topspin ball?

In terms of the amount of forward motion and forward hit the stroke seemed to me to be far more aggressive than a spinny lift. Almost as if he is hitting through the spin. Obviously it is coming from low to high but the bat speed allows him to be very aggressive and attack, rather than start up loop then attack.

Have a read here at the topspin(Loop) section http://www.experttabletennis.com/stroke-development-tips/

Where Schlager talks about BS or TS when looping. Statements like

The more topspin I put on the ball, the less I need to consider the existing rotation of the coming ball. The more spin I put on the ball, the less I need to consider the existing rotation.

Personally, I don’t see a clear difference between the topspin against topspin or backspin.

 

[Der_Echte]

i've noticed a lot of people (my self included) try to use the body by leaning into the shot, as in follow the shot with both shoulders. this is not good, the result is much better if you follow the ball with the playing shoulder and move the other shoulder back as this way your body gets a turning motion.

Kim Jung Hoon Advocates this pulling back of the non-hitting shoulder before moving the hitting shoulder forward as you describe, gives the shot 10 percent more power.

 

[strangeloop]

Kim Jung Hoon Advocates this pulling back of the non-hitting shoulder before moving the hitting shoulder forward as you describe, gives the shot 10 percent more power.

Interesting.. can you show a demonstration of that? I remember you posted a video series by KJH along with translation.. but I think I missed this point. So, let me see.. you bend your legs, put all weight on the right leg and then twist your waist, pull your non-playing shoulder backward, rotate your playing arm, snap the fore-arm and wrist and hit at the appropriate contact point whilst transferring weight to the other leg.. then comes recovery. Phew!! Breaking it down makes it look so complicated

 

[izra]

In terms of the amount of forward motion and forward hit the stroke seemed to me to be far more aggressive than a spinny lift. Almost as if he is hitting through the spin. Obviously it is coming from low to high but the bat speed allows him to be very aggressive and attack, rather than start up loop then attack.

Have a read here at the topspin(Loop) section http://www.experttabletennis.com/stroke-development-tips/

Where Schlager talks about BS or TS when looping. Statements like

oh it is far more an aggressive loop drive than it is a spinny lift. but that is due to the powerful body turn, and the hand is still doing some heavy lifting/spinning.

did you know that the chinese did a research paper about how spinny the national team members loops are? they found out the shot with the most spin was the loop drive, it had even more spin than the slow loop. so what ma long is doing in this video is very fast and powerful but it is also VERY spinny.

i agree with schlager in the sense that the mechanics of a loop are always the same and you only adjust the angle depending on the type of shot you are dealing with and you want to make. and also i agree that the more spin you produce the less careful you have to be... but that doesn't mean you can have a "one loop to fit them all", unless the incoming spin is quite low. take a look at how much schlager varied his loops in the world championship final against joo se hyuk.

 

[Boogar]

oh it is far more an aggressive loop drive than it is a spinny lift. but that is due to the powerful body turn, and the hand is still doing some heavy lifting/spinning.

did you know that the chinese did a research paper about how spinny the national team members loops are? they found out the shot with the most spin was the loop drive, it had even more spin than the slow loop. so what ma long is doing in this video is very fast and powerful but it is also VERY spinny.

i agree with schlager in the sense that the mechanics of a loop are always the same and you only adjust the angle depending on the type of shot you are dealing with and you want to make. and also i agree that the more spin you produce the less careful you have to be... but that doesn't mean you can have a "one loop to fit them all", unless the incoming spin is quite low. take a look at how much schlager varied his loops in the world championship final against joo se hyuk.

Jea i read that. wait let me search it... http://www.ittf.com/ittf_science/SSCenter/docs/199208013- Wu - Table Tennis Spin.pdf

I was impressed by two points:
- Loops drives have more spin than high loops, even though more energy is spent in hitting the ball flat.

They justify it that the player have trained the loops drive more and are better at using it. I think it also has to do with the way rubbers topsheet works together with the sponge. The rubber wraps more around the ball and gets more grip if you hit it flatter.

-Secondly Pips out player can reach similar spin! The highest pips out player had about 140 rotations per second and the best inverted had around 160 rotations! That's insane!
'
I wish there d be a tool to measure your spin! I bet mine is at like 30-40 max.

 

[songdavid98]

Jea i read that. wait let me search it... http://www.ittf.com/ittf_science/SSCenter/docs/199208013- Wu - Table Tennis Spin.pdf

I was impressed by two points:
- Loops drives have more spin than high loops, even though more energy is spent in hitting the ball flat.

They justify it that the player have trained the loops drive more and are better at using it. I think it also has to do with the way rubbers topsheet works together with the sponge. The rubber wraps more around the ball and gets more grip if you hit it flatter.

-Secondly Pips out player can reach similar spin! The highest pips out player had about 140 rotations per second and the best inverted had around 160 rotations! That's insane!
'
I wish there d be a tool to measure your spin! I bet mine is at like 30-40 max.

I'e always sort of suspected this, since I do power loop drives consistently. All you have to do is learn how to spin the ball forward (which is pretty hard, though). After that, you can just start looping harder and harder, and the ball will just keep getting more speed and spin. It will still go on the table, because you are looping forwards.

With the high loop, if you loop too hard upwards, you will go out, so there is like a pseudo-limitation.

The reason why most people think the high loop has more spin is because the spin to speed ratio is much higher.

 

[strangeloop]

That PDF is a great find. We often used to have this discussion here. I always used to feel that a closed angle with perfect contact can produce greater spin and speed. However usually I will be waging a lone battle. I think the mental image of spinning the ball with an open angle is more dominant than vs closed bat angle. Closed bat angle also needs greater hand speed compared to a vertical lift. It is possible to hit very spinny topspins with a closed angle. This is just my intuition. Likely to be half-wrong at least.

 

[Boogar]

That PDF is a great find. We often used to have this discussion here. I always used to feel that a closed angle with perfect contact can produce greater spin and speed. However usually I will be waging a lone battle. I think the mental image of spinning the ball with an open angle is more dominant than vs closed bat angle. Closed bat angle also needs greater hand speed compared to a vertical lift. It is possible to hit very spinny topspins with a closed angle. This is just my intuition. Likely to be half-wrong at least.

One thing about the high loops that makes you believe it has lots of spin is that the angle it comes at you is different.
Because the ball comes at you in a more vertical motion you need to adjust your angle more.
That's why its so hard to block a high loop ball and most people solve this problem by countering it.

 

[Ilia Minkin]

All you have to do is learn how to spin the ball forward (which is pretty hard, though).

I think that the hardest part of it is developing footwork & anticipation so that you get into position early enough to not mess up the timing. With slow loop it is easier since you can be late to the ball and still make the shot.

 

[NextLevel]

Guys, the fact that the loop drives have higher rotations per second is not news and in fact Hurricane is a relatively slow rubber. The fact that it is the spin to speed ratio for slower balls that is higher is not news and this is how serves or sidespin loops get their best curves.

In the end, it matter most what your customer doesn't like and whether you can produce it. Or a higher level, you just have to get good enough at what you do so that it hardly matters.

 

[Rajah*]

Kim Jung Hoon Advocates this pulling back of the non-hitting shoulder before moving the hitting shoulder forward as you describe, gives the shot 10 percent more power.

That 10%is a beast if executed perfectly. +1

Sent from my SM-G900F using Tapatalk

 

[NextLevel]

The physics work like this: If you take the ball early - off the bounce it has more energy and its rising. This means you don't need to generate that much energy by yourself and most importantly don't need that much lifting. That's why you can take it with a more horizontal motion. At least that's what they taught us in the trainer seminar and makes sense to me.

When you take it later on the ball is dropping, so you need to lift it with a more upward motion.

It's not so much about energy but about how the contact point on a ball for a loop changes when it is on the rise, at the top of the bounce and on the fall. It is easier to show with pictures, but it is also the reason why you can push a ball with a relatively closed paddle if you take it off the bounce as opposed to taking it on the fall, If you try to take really heavy underspin over the table after the top of the bounce, you will net it most of the time if it is below net height because the contact point for passive play as shifted to the bottom front of the ball and you are still trying to touch the back.

 

[NextLevel]

I'e always sort of suspected this, since I do power loop drives consistently. All you have to do is learn how to spin the ball forward (which is pretty hard, though). After that, you can just start looping harder and harder, and the ball will just keep getting more speed and spin. It will still go on the table, because you are looping forwards.

With the high loop, if you loop too hard upwards, you will go out, so there is like a pseudo-limitation.

The reason why most people think the high loop has more spin is because the spin to speed ratio is much higher.

The philosophy for looping with harder sponges and tacky rubbers is slightly different. There, you have to loop drive and because the catapult is relatively hard to get, you will get more spin and speed over a wider range of hard impacts than you will with softer sponged Euro rubbers. The trade off is ease of stroke speed at which the spin begins.

 

[Archosaurus]

The philosophy for looping with harder sponges and tacky rubbers is slightly different. There, you have to loop drive and because the catapult is relatively hard to get, you will get more spin and speed over a wider range of hard impacts than you will with softer sponged Euro rubbers. The trade off is ease of stroke speed at which the spin begins.

So there is a real benefit to hitting with A LOT of power as opposed to less power? The gains in spin from a slower action with more brush will be surpassed by the same original brushing action with more force?

 

[Boogar]

So there is a real benefit to hitting with A LOT of power as opposed to less power? The gains in spin from a slower action with more brush will be surpassed by the same original brushing action with more force?

I wouldn't call it power. More like momentum and racket speed of the bat. It's not like muscle power and hulk smashing stuff.

I notice this a lot with my H3N. Its hard to play slow controlled balls. However if I load and smash through ( ofc with the right bat angle) i get tons of spin and speed. Those hits need the most courage. However if you do it they feel much more safe and controlled.
On the other hand I always need too much time to get the feeling for the right stroke. So i can't use it in most matches.

EDIT: If I remember the feeling of those shots. I think i could play them against different spins with almost the same motion. Well not like heavy backspin and heavy top... more like no spin or a bit top or a bit back wouldn't matter. Which goes more into what Schlager says.