March 9, 2020

Tip of the Week
Proper Forehand Technique - Circling and From Side.

The Height of a High-Toss Serve
The question that has plagued the world for many centuries is just how high you should toss a high-toss serve. After all, the higher you toss it, the faster it'll be traveling when you contact it, giving you more spin, right? 

Actually, not really. Due to air resistance, any falling object in an atmosphere has a terminal velocity, but it varies based on its mass, cross-sectional area, drag co-efficient, air density, and gravity. For example, a little Googling tells us that a human body reaches terminal velocity in around 12 seconds - about 200 mph if falling feet- or head-first, about 125 mph if falling stomach- or back-first, with arms and legs spread out to maximize air resistance.

But how about a ping-pong ball? I found this online Terminal Velocity Calculator. For a ping-pong ball, the mass is 2.7 grams. The cross-section area is easy to calculate - it's the area of a circle with the diameter of a ping-pong ball, 40mm. Since A=Πr^2, and with radius 20mm, the cross-section area is about 1256.6 m^2. Some Googling found that the drag co-efficient for a sphere is about 0.5. Plugging these in, and using Earth's gravity and air density at sea level, we find that the terminal velocity of a ping-pong ball is about 18.55 mph.

But this doesn't tell us how high we have to throw the ball to get this maximum velocity. So I turned to my brother, Dr. Steven Hodges, a physicist and non-TT player (but great sailor!). He created this Excel file that does it for us.

So how high do you have to throw the ball to get to that magical 18.55 mph? Here's how my brother answered it - the first paragraph tells you most of what you need to know, the next rest are technical details.

Really, really high; falling objects approach terminal velocity asymptotically so, like Zeno, they never quite get there. But there is an answer to the practical question, how high do you need to throw the ball so when it falls back to the paddle (assuming the starting toss and paddle heights are the same) it is at, say, 90% terminal velocity.  The answer to that question is, using the parameters you provided below, about 20 ft.  If you want 99% of terminal velocity, throw the ball 40 ft high.

The attached spreadsheet shows the details.  Inputs are in red in cells C4 thru C7.  Terminal velocity is in C17 (ft/s), E17 (m/s), and G17 (mph).  The time from the ball's highest point (i.e., the height you throw it to, your input C6) to when it's back at the paddle is C19.  

If you change height thrown (C6) from 20 to 10 ft, the ball will only be at about 75% (between 74 and 79%) terminal when it gets back to the paddle.  You can find this by looking for the row where the height y(t) goes negative - y=0 is at the paddle; the fraction of terminal velocity is in column D.  

You can also play with the coefficient of drag to get an idea of how robust the model is. If CD is increased, you don't have to throw the ball as high to get a given fraction of terminal velocity, and vice versa.

Of course, this is all an approximation.  Probably good enough for what you're looking for, but the reality is much more complicated because the drag coefficient, air density, and even the ball shape, are not really constants - they vary during the fall.  So more exact solutions require simulations.  Here's an example that hints at the complexities involved: 

So there is our answer! In practical terms, I think most high-tossers throw the ball up at most ten feet, which gets the ball to 13.9mph. (If you throw much higher than this, you start to lose control and can't keep the ball low or skim it finely for maximum spin. Also, it's harder to be deceptive since if the ball is moving too fast, you can't do deceptive racket motions around contact and still control the grazing contact.) However, I am pretty sure some players have been known to toss the ball up to 20 feet (16.7mph), though it's probably hard to control. My club has 18-foot ceilings, and for fun I've done tosses that reach them - but since the toss is measured from where you toss the ball from and contact it, about three feet above the ground, that means a 15-foot toss. 

Here's video of the high-toss serve of Ma Long of China, the world #1 almost continuously from 2010-2019. Alas, I couldn’t find a video of anyone showing just how high it goes. (When they video top players, they zoom in, not out.) But you can tell it goes pretty high by how long he has to wait for it to come down. Here's a pretty high one by Shan Xiaona of Germany (world #50, formerly #14), but it also cuts off the highest part of the serve.

USATT Regional Hopes Camp and Tournament at MDTTC
See the link in Omnipong in the USATT section at the top for The 2020 USATT Hopes Program / Road to LA - MD. It's this weekend at my club, Maryland Table Tennis Center. I'll be coaching in the camp on Friday and Saturday, and running the Hopes Tournament on Sunday. This is for kids born in 2008 or after.

USA Table Tennis Teleconference Scheduled for Monday, March 9, 8:00 pm EDT
Here's the info page. Yes, it's tonight (Monday night)! I will probably listen in. As I wrote in my comment below this, I hope they will publish the agenda in advance (UPDATE - it's been added!), as well as put in the names of the current board in the Board Listing, which currently only has two of them, Niraj Oak and Tara Profitt. There are at least five right now - three others were named in this USATT news item on Jan. 31, Richard Char, Kristy Connelly Campbell and Kelly Watson. Even if they can't get their pictures up right away, it would be helpful to update the names, since they've been on the board for over five weeks now.

Coronavirus and Table Tennis
It's getting pretty serious! Many clubs around the country and the world have cancelled events because of it. Because there were three cases of it here in Montgomery County, MD, some of the local Chinese Schools closed this past weekend, and because of parents' concerns, our advanced junior program (Talent Development Program) cancelled their group session this past Sunday. My Thursday and Sunday Beginning Classes normally have 14 and 10 players, but both had only seven this time. For both, I was told it was because of coronavirus concerns. (In both of these junior classes, the focus was on pushing and smashing.) I've heard that players have taken to fist bumps or even "air bumps" rather than shaking hands - and I've adopted fist bumps as well.

I'm heard private estimates that it's 50-50 the Olympics in Tokyo will be postponed or cancelled, though I have no idea how accurate these estimate are. (I'm supposed to fly out to do USATT coverage on July 23.) Here's an article on it from the BBC, Will coronavirus cancel the Tokyo 2020 Olympics? (Long-serving IOC member Dick Pound "last week admitted a decision to cancel could be made as late as May.") But the World Championships have already been postponed, and the Italian and Japan Opens in April and the Australian and South Korea Opens in June have also been postponed. (Here's the ITTF calendar where you can see which ones have been postponed.) C'mon, people, wash your hands - we don't want to postpone or cancel the Nationals in July!!!

Am I the only one to notice that "coronavirus" is an anagram for "carnivorous"? Very dangerous virus indeed!

USA Olympic Team Trials
In my blog last week I linked to the 16 articles I wrote on this. While there will always be debate on the format, I actually liked this format. After the various preliminaries (which got the players down to 16, for both men and women), there were two groups of eight. After they played it out, the top four went to a Final Four. The good part? The large number of high-quality matches was incredible for bringing out the best from the best, who rarely play that many that close together. It's like a month of intense training condensed into 3-4 days. Of course, the downside of such RR formats is that there's always the problem of dumping in the final rounds - partially fixed by having players from the same family or club play early, and having the top seeds play each other at the end.

I heard someone thought I got paid a bunch for this trip. Actually, I was a 100% volunteer - I didn't get paid a penny except for expenses. I came two days early and stayed two days late to do some sightseeing, but I paid for my hotel, food, and everything during that time.

As to the sightseeing in the Santa Monica/Los Angeles/Hollywood region, I visited the Walk of Fame, Hollywood Sign, Griffith Observatory, Santa Monica Pier, Hard Rock Café, Ripley's Believe It or Not, Guinness Book of Records, Hollywood Wax Museum, Paramount Pictures, La Brea Tar Pits, Los Angeles Zoo, Los Angeles Natural History Museum, California Science Center, and spent the last day at Universal Studios.

I was also on a 70-minute teleconference on Tuesday morning with the press people from the USOPC (interfering with my time at Universal Studios, grumble, grumble). Assuming the Olympics takes place on time, I'm flying to Tokyo on July 23 to do coverage for USA Table Tennis (again, as a volunteer, with only my expenses paid - I think USOPC is covering much of that, not sure).

Invitation to Members Interested in Committee Service
Here's the USATT press release. They are looking for the following:

  • Ethics and Grievance Committee (3-5 members, including the Chair)
  • Nominating and Governance Committee (1 member)

Forehand Loop Demo
Here's the video (3:30) by Dora Kurimay.

New from Tom Lodziak

New from Samson Dubina

New from eBaTT

Together and Apart, Eugene Wang and Zhang Mo Book Tokyo Places
Here's the ITTF article. There was a USA-CAN Mixed Doubles match for the North American Mixed Doubles spot at the Olympics, with Zhou Xin and Liu Juan for USA, Eugene Wang and Mo Zhang for Canada. Canada won, 4,7,-10,5 - here's the video (30:37, play actually begins around 4:30).

Qatar Open
Here's the ITTF page for the event held in Doha, Qatar, March 3-8, with complete results, articles, pictures, and video.

It's been two weeks since I last linked to their articles (since I was away last week), so why not browse the ITTF News Page?

New from Butterfly

World Table Tennis
Here's the ITTF's new World Table Tennis. See their Vision/Mission page, Key Benefits page, and Info Video (1:24).

Here's their page - "Stay in the loop, find everything table tennis. Search new or used equipment, places to play, coaches and events."

ICC Table Tennis Center Hosts USATT Hopes Tour Appropriately Coinciding with Olympic Trials
Here's the USATT article by Michael Reff.

Local Senior Athletes Find a Lifetime Sport in Table Tennis
Here's the article, featuring the Washington DC Table Tennis Center, and past owners Charlene Liu, Changping Duan, and new owner Khaleel Asgarali.

11-year-old Syrian Table Tennis Player Hend Zaza Qualifies for Olympics
Here's the article and video (1:26) from CNN. It mentions that she's 155th in the world, but that's misleading - that's her ranking for Cadets (under age 15).

Anyone Can Try Out for the U.S. Olympic Table Tennis Team, So We Did — and Here's How It Went
Here's the article from Fox Sports - but the author was not just any player, it was Martin Rogers, rated 2288 - a top player by most standards, just another amateur by Olympic standards.

USA Table Tennis Bans Hitler from Olympic Trials
Here's the video (20 sec)! Yep, I put this together, and linked to it before, but thought this was a good time to link to it again. (I also wrote, "Releasing Hitler"!)

Hypergalactic Psychic Table Tennis 3000
Here's the info page and video (1:44) for this new table tennis game! Here's their press release. I emailed with the inventor, and she wrote me, "One cool thing is that you can actually play against Al Alcorn, the original creator of Pong (the very first video game!) - when we reached out to him about the game, he jokingly sent us a voice message saying 'Oh my God, what have you done to my Pong?!' but also really loved it and thanked us for caring about Pong, and said 'have fun with it'..."

Here's what one reviewer wrote:
"Hypergalactic Psychic Table Tennis 3000 is a game of pong with a few twists. It starts out as simple pong but you soon start leveling up which allows you to increase your size and learn skills. Keep playing and battling and you'll soon be shooting fireballs, teleporting, and reading minds. There are a variety of enemies that you face over the course of the game. Each game you play to three vs the AI. There are two hundred levels in a loop and after that you can either new game plus it or you can start from scratch. You can also go through romance dialogues with the bosses. You hit a boss every ten levels or so; so that makes 20 romancable paddles. You can stylize yourself with fancy treasure you find along the way which is neat."

New from Coach Jon

New from the National Collegiate Table Tennis Association
They've been busy, holding their regionals.

New from the Malong Fanmade Channel

2019 ITTF Parkinson World Table Tennis Championships
Here's the highlights video (2:46). I coached Navin Kumar at the tournament - Silver in Doubles, Bronze in Singles. (You can see me briefly at 1:43 on the right.)

Chen Xingtong | Ask A Pro Anything
Here's the ITTF video (5:05) from Adam Bobrow.

New from Pongfinity
No humorous videos this week - instead, it's video of one of their players, Miikka O'Connor (world #845, but #439 last year), from the Finnish Championships! He made it to the final before losing to World #95 Benedek Olah.

Kim Taek Soo vs. Jang Woojin Exhibition
Here's the video (11:38), both from South Korea. Woojin is world #16. Kim was a big star in the 1990s - here's his Wikipedia entry. Check out his Medal Record on the right, and you'll notice something extraordinary. At the Olympics, he won two medals (Singles and Doubles), both Bronze. At the World Championships, he won nine medals - one for Singles, four each for Doubles and Teams - and all nine are also Bronze! Then you go to the World Cup for Singles, and he has three medals - all Silver! He did win Gold at the World Cup and Asian Championships, twice each for Doubles and Teams. I believe he reached #3 in the world. He is now the head coach for the South Korean Men's Team.

Engineers Design 3D-Printed Table Tennis Paddles for Oculus Touch Controllers
Here's the article and videos!

Amazing Kids - Game Show Table Tennis in China
Here's the video (3:19)! It's in Chinese with English subtitles.

Three-Paddle Pong
Here's the video (16 sec) featuring a "cheating" Matt Hetherington.

Z Table Pong
Here's the video (3:39)!

Ellen DeGeneres Challenges Child Ping-Pong Star Yiyi as Melissa McCarthy Refs
Here's the video (4:17)!

Happy Table Tennis Birthday
Here's the video (1:23) of the table tennis birthday song!

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