The Big Point

I just read a thought-provoking article at TennisOne titled, The Trap of the Big Point Theory, by Happy Bhalla. Mr. Bhalla's thesis boils down to two points, 1) that all points are equal, and 2) even if this weren't true, it is unwise to council players to play points in any manner but the best manner.

This is a topic that I have been considering for a few years. A comment by a fellow pro during a women's NTRP 3.5 team practice sparked my interest. We were talking about tie-breaks and the pro said, "You should pick up your play during a tie-break." I've heard some variation of this advice fairly frequently and given it myself in the past. The obvious question is, if you have a better level, why have you waited until a set is tied at 6-6 to bring it out? Since I can't come up with a reasonable answer to that question, I've given up telling people to pick up their level of play in tie-breaks.

To discuss big points in tennis, I think we must have a definition of big points. Mr. Bhalla seems to divide points into two categories, big and not big. I don't think this is sufficient. I think there are degrees of bigness to points, just as there are degrees of bigness for players – some are over six feet and some are under six feet, but some of those over six feet are bigger than others over six feet. In stating his case that all points must be equal, Mr. Bhalla offers up a contrasting opinion from Brad Gilbert. According to Bhalla, Gilbert defines big points as points that win games or points that lead to points that win games. Mr. Bhalla then shows that logically the point preceding the point that leads to a point that wins a game must be just as important. By this logical chain, if any point is big, all points must be big. And that's indeed what Mr. Bhalla says, "At the very least, we would have to call each point big. Actually, they are equally important or equally insignificant, with the emphasis on equal."

So for Mr. Bhualla, all points are equal. If tennis were a game played with a clock where the player accumulating the most points at the end of the playing time wins, then Mr. Bhulla's logic would be valid. Basketball, football, soccer, hockey and many other games fall into this category. Tennis, however, does not.

We can show that all points are not equal by focusing on how tennis matches end. In order to win a match, one player must win two out of three sets (in some cases three out of five). In order to win a set, one player must win six games with a margin of two games (or win a tie-break at 6-6). In order to win a game, one player must win four points with a margin of two points. This scoring system places unequal emphasis on points. This system allows us to rank particular points in relative importance. A match point (defined as a point that, if won by the leading player, will end the match) is the biggest of the big points. If player A holds a match point on player B, a loss of the match point will lose the match for player B. No other point is as big (though there can be multiple match points in a match, each big). How would a set point in a non-decisive set rank in relation to a match point? It must be of lesser rank since a set point in a non-decisive set cannot end the match. Therefore we know that a match point is higher ranked than a set point in a non-decisive set. We have proven that all points in a tennis match are not equal.

We can continue this exercise to rank a game point in a game that does not determine the winner of a set. Such a point must necessarily be of lesser rank than a set-point since it does not end a set. Therefore a non-decisive game point is lesser ranked than a non-decisive set point which is lesser ranked than a match point.

Finally, we can rank a point which does not decide a game. Such a point must be of lesser rank than a point which does determine the winner of a game. So our ordinal ranking of points in a match, from lesser to greater rank, or from small to big if you want to call them that, goes as follows. A match point is bigger than a set point. A set point is bigger than a game point. A game point is bigger than a non-game point.

All that is of course trivial. What we're really interested in is not whether a match point is a big point or not. Of course it is. Nor are we intersted in whether set points or game points are big points. Again, of course they are. Mr. Bhulla would almost certainly not dispute this. But what about supposed big points within games, which is the emphasis of Mr. Bhulla's assertion that all points are equal? Can we put a relative value on them? Yes. That isn't as easy. Thankfully, Dr. Howard Brody has already done the heavy lifting for us.

In his book, Tennis Science for Tennis Players, Dr. Brody uses conditional probabilities to show which points within a game are the most important. Dr. Brody defines the "importance factor" as "the probability of winning the game if you win the point, minus the probability of winning the point if you lose the point." Instead of classifying points into big and not-big, Dr. Brody offers us a way to rank points on their importance, clearly defined.

Dr. Brody does this and presents the results in tabular and graphic form in Chapter 8 of his book. The results clearly indicate that all points within a game are not equal, since the importance factor varies from over 0.69 to under 0.05. That is a wide spread. Therefore, from match points and set points on down to various game points and points within games, we can conclude that some points are more important than others.

Having disproved Mr. Bhulla's assertion that all points are equal, we still must deal with his second point, that even if some points are bigger than others it is unwise to council players to play some points differently from others. I'm sympathetic to Mr. Bhulla's position on this issue. As my anecdote about tie-breaks conveyed, I am hesitant to tell people to "pick up their games" when they get to a tie-break. But does it follow that players should not play certain points differently earlier in sets, or even use different strategies for different points in tie-breaks? I'm not sure that it does.

As Dr. Brody pointed out in his introduction to Chapter 8 in Tennis Science for Tennis Players, tennis players have finite energy reserves. If a player exerts himself or herself maximally throughout a match, isn't it possible that he or she will have less energy at the end of a match than someone who has expended energy more judiciously?

Jack Kramer explicitly advocated this strategy. I remember reading a tennis instruction book by Mr. Kramer where he said that players should not expend energy to break serve unless they had a 0-30 lead or more. I even think I remember reading that Kramer said the worst mistake a player could make was to hold to go up 5-3 in a set and then expend energy trying to break serve to win the set with a break. Instead, Kramer said, a player should take it easy in the 5-3 return game, rest and get some water at the 5-4 changeover, and then serve out the match. Clearly Mr. Kramer didn't think all points were created equal. Mr. Kramer realized that the odds heavily favored him, and most male players in the era of grass-court tennis, when serving. He also realized that a tired server is less likely to hold than a rested server. Though I never adopted this strategy myself (lacking Mr. Kramer's serve and volley prowess), I find it hard to argue with his logic.

In addition to the differing probabilities dictated by the serve and the finite energy reserves of all players, I think it's also wise to use the different importance of points within a match to try alternate shots, tactics, or strategies. Mr. Bhulla, in his TennisOne piece, claims that a player can only be surprised once. I think is too narrow a definition of surprise.

Just as we did above regarding "bigness" of points, I think it's wise to allow for levels of surpise. I think that a player's ability to predict the next shot can be used as a proxy for his likely level of surprise. If he is likely to accurately predict the speed, location, or spin of the next shot, I would say he is not likely to be surprised. However, if he cannot accurately predict which shot is coming next, he is more likely to be surprised. This does not mean that a player, in order to be surprised, must have never seen a particular shot or tactic before. It only means that he shouldn't be able to anticipate the next shot or tactic with certainty.

Using this, rather than novelty, as the definition of surprise, I think it is wise for a player to set up future confusion by introducing multiple shots and tactics at less important points in a match. If a player uses a variety of shots and tactics in the lead up to a bigger point, it is less likely that an opponent will be able to predict which shot or tactic to defend against on a big point. Of course, any alert player will expect a shot or tactic that has been successful earlier. If player A is able to establish multiple successful shots and tactics against player B in the early games of a match, then player B will be less likely to anticipate the shot or tactic employed by player A on big points. I think there is value in this approach to match play.

I said that I am sympathetic to Mr. Bhulla's viewpoint regarding big points. From my discussion so far, that may seem confusing. I disagree with Mr. Bhulla that all points are equal. Since all points are not equal, I think that fact offers some opportunity for exploitation and experimentation. However, I think Mr. Bhulla is likely right when he says that the best players probably gain a reputation for playing the big points well because they play all points well. I also think that it's quite likely that poor players play even more poorly on big points, while better players are better able to maintain their higher level of play on the bigger points. [Two economists from Europe looked at all matches played at Wimbledon over a four year period in the 1990s and found that for the men, the better players did appear to play better on the bigger points, while that did not appear to be true for the women (link to research paper, which is a wonderful examination of several commonly held beliefs).] Nor have I come to any conclusion about how to council players to play what I consider to be big points other than to play their best. I am a big advocate of trying to figure out what the highest percentage plays are and sticking to them.

I do not share Mr. Bhulla's implied belief that playing within oneself means giving up opportunities to attack. Here is how Mr. Bhulla phrased that in his article,

"Another theory suggests that one should play within oneself on [big] points and avoid giving away easy points; however, giving up opportunities to attack allows the opponent to gain the initiative."

I agree that "giving up opportunities to attack allows the opponent to gain the initiative" and that such a tactic on big points would be foolish. However, I don't think it follows that "playing within oneself" implies "giving up opportunities to attack." Since the rest of the piece is quite well thought out, I don't think that Mr. Bhulla really thinks that it does either. I think what he meant to convey in this passage was that to play passively on big points in order to avoid giving points away is foolish. I agree with that. But I think that players can seize opportunities to attack, while still playing within themselves and not giving away easy points. As I said, I'm pretty confident that Mr. Bhulla would agree with this, too.

I'm glad that Mr. Bhulla took the time to write his article. To challenge tennis orthodoxy, and to challenge those who challenge orthodoxy, helps move the game and the coaching profession forward. By jumping into the ring and throwing a well-reasoned punch in the tennis theories boxing match, Mr. Bhulla has done the game a service.

SET Ratings

A few days ago I came across a web site that applies the chess rating system to men's professional tennis. The data set is limited to the open era, so fans of Tilden, Budge, Kramer and Gonzalez won't find their men rated.

Don’t Become a Delegator When It Comes to Learning

"We give [the players] a lot of responsibility. We never call plays. The first pass dictates things and sort of teaches them how to play. Our defense is the same way. I don't tell them who they're guarding. They've got to figure things out on their own."

That’s Joe Scott, Head Men’s Basketball Coach at the U. S. Air Force Academy in Colorado Springs, CO describing his Princeton System of basketball. Scott’s players know their success rides on their ability to learn the system and execute under pressure. They accept that responsibility. Possibly because of that mindset, they are having the best year in the history of the Academy as I write this.

Independent thinking is a hallmark of success, especially in open skill competitions like basketball or tennis. If you find yourself looking to a coach all the time to explain why something went wrong, or to tell you where to be or where to hit a shot, perhaps you need to take responsibility for learning these things on your own. A coach, no matter how good, cannot learn these things for you. Learning is not a team sport. Even in sports like basketball where the coach is on the sidelines barking out instructions, the players must know what to do, recognize changing conditions, and adapt their actions accordingly. No coach can do that for a player.

For this reason, among others, I disagree with people who say coaching should be allowed during tennis matches. In fact I’d ban it in Davis Cup, college and high school competition just like it’s banned everywhere else. I’m highly skeptical of the value of coaching during game situations, and am aware of the danger of players becoming dependent on coaches, to the detriment of the players.

A coach can help prepare players for competition, but ultimately players play. Players who understand and accept that get the most out of athletic competition.

Acquisition of Technique in Tennis and Golf

In the new “What is EASI Tennis?” introduction, Ray and Becky wrote the following:

“What we observed was, that although tennis was making great advances in teaching nutrition, conditioning, footwork, tactics and strategy, advancements in teaching technique were proceeding at a snail's pace. This was puzzling because other technique intensive sports such as gymnastics, ice skating, football, golf, and track and field, were advancing rapidly. We wanted to know ‘WHY?’.”

I’m in a pretty good position to comment on this as it relates to particularly tennis and golf. I played Division I college tennis twenty years ago and before that twice defeated a future grand slam doubles champion, once in Kalamazoo at the U. S. National Junior Championships. After college I turned to golf as my main hobby and in a few years managed to very briefly get my handicap just below zero. I worked in the golf industry for several years and helped out with junior instruction along the way. After a ten year hiatus from tennis, I returned to teaching tennis part time, which I’ve now done for ten years. Even though I’m now a tennis pro, I still have friends in the golf instruction business, and one acquaintance who plays on the PGA Tour. I don’t have the answer to Ray and Becky’s question, but I think I have enough background to offer some insight into what it takes to succeed in tennis and golf, and the role that instruction plays.

My own experience shows that instruction is not necessary to get pretty darn good at both games. I never once had a private tennis or golf lesson. I did benefit from the help of some wonderful coaches in tennis, but I don’t recall a single instruction on technique from any of them.

The experience of my friend on the PGA Tour shows that a person can rise to the PGA Tour without instruction. He is now in the top 20 in the world and may have had a little instruction lately, but I know that he rose to the level of the tour without any formal instruction. He was and is a self-taught player.

This doesn’t mean that technical instruction is never helpful. It does mean that technical instruction isn’t a necessary ingredient for athletic success at very high levels.

To take this a bit further, the examples from golf of Ben Hogan, Byron Nelson, Moe Norman, and Lee Trevino reinforce my assertion that technical instruction isn’t necessary. The four gentleman I’ve listed have two things in common. The are acknowledged as the four best ball strikers in the history of the game. None had technical instruction.

What about the recreational player? I know that golf instruction has become more technologically advanced than tennis instruction over the last twenty years. Videos and computers are a common element of golf instruction now. I have not seen any evidence that the technique of the recreational golfer is any better now than it was thirty years ago. The equipment is better, but the scores and the swings seem to stay about the same.

Tennis has not kept pace with golf in the use of video and computers to aid instruction. That is changing, thanks to people like Ray and Becky, and soon with the help of Brian Gordon and his 3D data analysis software. The typical recreationally player’s technique seems to be no different to me now than it was when I started playing in the early 1970s.

That cannot be said of the tour pros in tennis or in golf. The tour professionals’ technique has evolved in both sports. It’s not clear that this evolution is instructionally driven, though. I think that the use of video and computers may have reduced the variance in playing styles on the PGA Tour (the swings do look more similar to me than the swings of pros thirty years ago). But the same can be said of players on the ATP Tour. The variation in technique has gone down there, too. So while videos and computers can be thought to have contributed to the changes in pro golfers’ technique, the absence of such technological aides has resulted in similar changes in tennis pros’ technique. I think looking elsewhere for the reason is warranted.

"I took my eye off the ball."

Have you ever framed a shot and said to yourself, “I took my eye off the ball?” Who hasn’t? But did you ever ask yourself, “When did I take my eye off the ball?” Perhaps you’ve read or heard that you are supposed to watch the ball into contact, or watch the ball hit your strings. Maybe you’ve heard that it’s important to have the ball in focus at contact.

I’ve heard all of those things and even said some of them. Just because people say things and believe things doesn’t mean they’re true. Fortunately we have a method at our disposal for distinguishing assertion from fact -- the scientific method. Carl Sagan called it a candle in the dark. It’s really quite simple to use. The other day I used it to check the validity of the above statements.

I began with the following hypothesis: It is important to focus on the ball at contact.

To test the hypothesis, I designed the following experiment that you might want to try yourself.

1. Repeatedly bounce the ball upwards off your strings (self volley) to roughly eye height.
2. Establish that you can do this self volley with your full field of vision.
3. Next use your non-racquet arm to block your racquet, hand, and arm from your field of vision (while still allowing yourself to see rest of the ball’s trajectory including its peak).
4. Repeat the self volley with your vision occluded as described in step 3.
5. Try varying the amount of the ball’s path you can see, but never allowing yourself to see contact.

I discovered that as long as I could see the ball as it peaked, I had no trouble maintaining the self volley. Conclusion: my hypothesis is wrong.

Then I tried the following experiment to test this hypothesis: If I focus on the ball at contact, I don’t have to see the rest of the ball’s flight path to maintain a self volley.

1. Self volley as in the first experiment using your full visual field.
2. Block your vision of the flight of the ball except for the ball and racquet contact and a foot or so of the ball’s travel above the racquet.

I found this to be extremely difficult. Conclusion: my hypothesis is wrong.

From this further experiments come to mind, but I’ll leave those to enterprising readers to design. I feel pretty comfortable concluding that seeing some portion of the ball’s flight other than the moment of contact is important.

I have to admit that the results of these experiments didn’t surprise me because I’ve played tennis for a long time. I’ve also seen lots of photos of players at contact, and I’ve read the research literature into visual tracking in sports. I have hit plenty of balls behind my back and I can assure you that I don’t have eyes in the back of my head. I’ve also seen countless photos of pros hitting shots in which the pro’s eyes are not focused on the ball and are even closed at contact (Hingis appeared to blink at contact quite frequently). Tough to watch the ball meet the strings if your eyes are closed. I’ve also read studies of tennis players, volleyball players, and baseball batters who have been observed in controlled conditions tracking incoming balls. The players have been fitted with goggles that monitor the focus of the players’ eyes. Except for on rare occasions, none of the players focused their eyes on the ball at contact. Is there a better way to track the ball than the way that these players track the ball? Maybe. The way to find out is to try some experiments like the ones I did. From my experiments we moved one step closer to understanding why people hit the ball poorly by potentially ruling out one reason. More specifically we falsified the age old hypothesis that it is important to watch the ball into your strings.

Now if you catch yourself saying you took your eye off the ball on a mishit, ask yourself “when?” you took your eye off the ball. It may be that you did take your eye off the ball at some critical moment in the ball’s path. But maybe something else caused the mishit, like a sudden movement or a simple misalignment of your racquet. Those things do happen without a vision mistake. By avoiding a fixation on something that isn’t likely to have caused your error, I think you’ll be more likely to figure out what did.

"I saw that one wide."

I’m playing doubles with Gary against Pete and Andre. I am ready to return serve just behind the baseline in the deuce court and Gary is standing on the service line in the ad court three feet to the left of the center line. After netting his first serve, Pete hits a second serve wide to my forehand. As I lunge to my right to play the ball Gary calls,“Out!” Gary saw the ball wide and made the call. I wasn’t sure it was wide and without Gary there would not have called the ball wide. Pete and Andre protest that Gary was in a poor position to make the call--he was a long way from the far sideline and he had to look across the line to make the call. Pete and Andre say it’s my call. Are they right?

The Code says the view down the line is better than the view across a line. Line judges are positioned to look down lines. It looks like Pete and Andre are right.

But wait. I’m not a stationary line judge. I was watching the ball, but I was also moving and reacting in an effort to play the ball. My angle was the same as the hypothetical line judges’, but I wasn’t just standing there waiting to make a call. Gary was. So in that respect, Gary’s perspective was more similar to the line judge’s perspective than mine was.

What about the claim that the ball was on the far sideline a long way from Gary? The closest I got to where the ball bounced (before lunging to my right to play the shot) was when I was at the baseline. The baseline is 19 feet from the service line. Gary was 3 feet from the center service line. The service box is 13.5 feet wide. That means Gary was about 16.5 feet from where the ball bounced. Gary was closer to the bounce of the ball than I was.

Hmmm. Now I think Pete and Andre don’t have a case. But what about the nagging question of the angle, the line of sight relative to the line? Let’s have a look at that.

Being of a scientific nature, I decided to check this out before accepting it as fact just because The Code says it’s true. A simple experiment easily cleared this up for me. I placed a ball as close as I could to the line, but wide. When viewed from Gary’s position the ball looked wide. Gary could see the space between the ball and the line. Viewed from my perspective, the middle of the spherical ball covered part of the white of the line. That meant the ball looked in. As I moved to my right outside the sideline, the ball looked even more like it was in. If the goal is to tell if a ball is out, Gary’s view across the line was better than my view looking down the line.

The Code is wrong. Gary’s view was superior. Our call stands.

On the very next point, Pete hits a first serve to Gary that Gary rips up the line past Andre for a winner. Andre never budges. He says Pete’s serve was long. The serve was moving awfully quickly, but it looked to me like it caught the back of the line so I didn’t call it out. Andre thinks Pete should hit a second serve? Should he?

Nope. The rule is clear. It’s our call. We played it and we won the point. This situation comes up a lot, especially in doubles when the server’s partner tries to call a serve first serve long. To see why this happens, just return to the discussion of the prior point. Since Andre is standing close enough to the net that he can see the service line over the top of the net he’s in the best position of all the players on the court to see the space between Pete’s serve and the outside edge of the line. Therefore, Andre will correctly see a ball that is barely long, whereas Gary and I won’t be able to call it long, since from our perspective’s we can’t see the space between the ball and the line.

Pete and Andre are wrong on both counts, and even The Code is wrong on the first one. At least that’s how I see it.

BRG

Welcome to BRG's new weblog. Enjoy.