April 23, 2018

Tip of the Week
Are You a 10-8 or an 8-10 Player?

Happenings

  • MDTTC Talent Program Party. Last night we had our Talent Program Party at MDTTC, which we do about every six weeks. It took place after the usual 5:30-7:15 PM session, which is for our best and most dedicated kids, mostly ages 7-13. (The Talent Program is run by HW Global Foundation.) First up was buffet style Chinese food. (I had sesame chicken and beef with broccoli, on rice.) While this was going on our coaches met with the players and parents and went over how they have developed over the past six weeks. Then it was fun time - the kids and coaches went out on the table and battled it out with over-sized rackets, mini-rackets (with Tenergy), over-sized balls, and Wobb-Ball!
  • Beginning Junior Class. In the 90-minute session on Monday the focus was on spin serves, and then footwork - lots and lots of footwork!!! As usual, the last 30 minutes was games - the older and stronger players played up-down tables (11-point games), while the younger ones did what they always want to do - build large towers and walls of paper cups, and then knock them down as I feed multiball.
  • Saturday Junior League. They meet 2-3 times/month, but it's not really a league - it's more coaching the league play. We started with doubles, and then singles. For the singles, we often have them play with improvised rules. For example, we played games where if the receiver could stop the server from attacking the first ball, he immediately won the point, and if the server did serve and attack and won the point, he'd get two points. Another was that the score started at 7-9. This would greatly favor the receiver except for one additional rule - if the server won the first two points to tie it at 9-all, he immediately won. Sometime I'm going to do a mathematical study on who is favored in this type of game - but if any of you want to do it, comment below!
  • Shoulder Update. As I've blogged previously, they are mostly working on the muscle around the shoulder, which are abnormally tight and only have about 50% normal range. (I meet with the physical therapist three times/week for 90 minutes, and do two 20-minute stretching routines each day.) Meanwhile, the shoulder injury itself, while in theory should be healing, doesn't seem to be getting much better. But until the surrounding muscles are looser and no longer pulling on the injured part, there's not much that can be done on it. I still might have surgery later on, but the earliest might be summer, and it might not be needed. It seems like about once a day I'll do something that at least slightly aggravates it - I'll reach across a table for something and go "Ow!", or forget to use my left arm to support my right when combing my hair or reaching for a light switch, or reach up in my car to turn on the overhead light. During a group session yesterday I hit easy forehands with a beginner - and held my right elbow in with the left arm to make sure I didn't extend the arm and hurt the shoulder, and it worked pretty well.
  • Lefty Multiball. Due to my shoulder problems, I've experimented with this recently. (I can feed regular topspin normally, but when I feed repetitive backspin it aggravates the shoulder injury.) I ca do it borderline adequately. I'm starting to get decent backspin. I still don't have anywhere close to the control I have right-handed, but it might be okay for beginners.
  • Regional Hopes Camp and Trials. It's this Fri-Sun. Friday afternoon and night and all day Saturday I'll likely be feeding multiball, then I run the Regional Hopes Trials on Sunday. These are for kids who were born in 2006 or 2007. Other junior players are allowed in the Camp on a player by player basis.
  • Avengers: Infinity War. It's in three days!!! I coach a junior class from 6:30-7:30PM, and plan to go straight to the Germantown theater afterwards for an 8:30PM showing. I plan to order a chicken sandwich (dinner), small popcorn (easy on the butter), Mr. Pibb, and because this is an "event" movie, perhaps Reese's Pieces.

National Collegiate Championships
They were held this weekend, Apr. 20-22, in Round Rock, TX. Here are some links.

$2700 3-Star Butterfly MDTTC April Open
Here's the article, results, and photos on the tournament I ran last weekend.

Progressive Training Explained
Here's the video (3:11) from Samson Dubina.

Table Tennis Push Techniques
Here's the article from EmRatThich.

New Videos from EmRatThich
Here's been busy!

World Table Tennis Day: Nominated for 2018 Sports Business Awards
Here's the ITTF article and photos.

ITTF and Twitter Announce Live Stream of 2018 Challenge Series
Here's the article.

ITTF Legends Tour 2018 Teaser
Here's the video (1:04). This year's ITTF Legends Tour players are Werner Schlager, Jean-Michel Saive, Kalinikos Kreanga, Zoran Primorac, Mikael Appelgren, and Jiang Jialiang.

Trick Shots from Pongfinity
Here's the video (2:02)!

Little Door Trickshot
Here's the video (41 sec) as Liu Guoliang smacks three balls - one to open a tiny door, one to smack away a ping-pong ball, and one to lose the door.

Captain Jack Sparrow vs. Ragetti
Here's the picture! (Here's the non-Facebook version.) Sparrow is of course the main character from the Pirates of the Caribbean movie franchise, while Ragetti is a recurring comic character.

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Re: April 23, 2018

To answer your question about your improvised game. it all depends on their ability to win points on their serve.

Given two equal players, FS (first-serve) and FR (first-receive), starting at score 7-9, with FS winning if they score the first 2 points on their serve, then FS will have the advantage if they average winning 69.3% or greater of their serves, and FR will have the advantage if they average winning 69.2%  or less of their serves.

Analysis: If the score reaches 10-10, then neither side will have any advantage, since they are equal players. So it only depends on who has the advantage in games ending before then.

FS can win before 10-10 only if they win the first 2 points.  FR will win if they either win both of the first 2 points, or win 1 point on FS's serve and then 1 point on their own serve.

Mathematically: if S is the chance that the player will win a point on their own serve, then

FS will win S*S  (if S is 2/3, then FS will win the first 2 points 2/3 * 2/3 = 4/9 of the time)

FR is mathematically more complicated (works out to 1 - 2*S + 5*S*S - 6*S*S*S + 2*S*S*S*S).  If S is 2/3, then the chance of FR winning before 10-10 is 1/9 if they win both of the first 2 points (1/3 * 1/3) plus 32/81 if they win one FS serve point (4/9 chance) and at least one FR serve point (8/9 chance).

Since 1/9 + 32/81 is more than 4/9, FR has the advantage if S is only 2/3.

The point of equal advatange works out to be a bit greater than .692.  If S is greater than that, then FS has the advantage; if S is less than that, then FR has the advantage.

Larry Hodges's picture

Re: April 23, 2018

That's a great analysis! Since among roughly equal players essentially nobody wins over 69% of the points on their serve (meaning they must lose 69% on the receive), this means the advantage is normally to the receiver. However, in lopsided matches, where the server would win over 69.2% of the time (or round up to 70%), then the weaker player should choose to serve. I'll let the coaches and kids know. Appreciated!