08/19/2013 10:24 am ET Updated Oct 19, 2013

Is It Legal? Yes. Ethical? Perhaps. Underhanded? Definitely.

As tennis players gear up for their next Grand Slam, the U.S. Open, here's a bit of now obscure Slam history: The most famous underhand serve in the history of professional tennis remains a severely cramping Michael Chang's deft trickery that unnerved a choking Ivan Lendl in the fourth round of the 1989 French Open, enabling Chang to retain his fifth set lead and go on to become the youngest men's major champion in history. However, the fact that the golden day of the underhand serve was almost 25 years ago pretty much tells you what you need to know about how frequently this tactic is deployed. One reason the underhand serve is so rare is a matter of simple physics: Given the dimensions of a tennis court, you can exert greater force and spin on an object by hitting downward in a fairly straight line than upwardly parabolic. The other reason is a matter of ethics: Underhand serves are perfectly legal -- the International Tennis Federation (ITF) Rules of Tennis (#16) says only that the ball must be struck "before the ball hits the ground", and the United States Tennis Association adds a comment (#16.1) that a player may serve underhand as there is "no restriction in the rules on the kind of service motion that a server may use." But underhand serves, especially when they are perceived to provide a performance advantage, are ethically questionable, perceived as deceitful trickery, and, in a word, underhanded. Should they be?

Before we try to answer that question, let me explain why it might matter. My reasons for caring including one having to do with tennis and another not: The tennis reason is that I am a competitive player coming back from an injury. For several weeks, I have only been able to play below-the-shoulder. During that time, in the only doubles match in which I brandished my underhand serve, my partner was irritated -- it made him a sitting duck at the net -- and our opponents were also annoyed, as though we weren't playing real tennis. I felt compelled to explain that I was using this ploy out of physical necessity, not because I was engaging in gamesmanship. Alas, they had little sympathy and broke my serve. The problem with an underhand serve is that if your opponent knows it's coming, a good player will feast on it as he would any short ball. As an exclusive method of serving, it's a bad strategic play. But now, with my body recovering, I've been thinking of mixing in some underhand serves for a change of pace and element of surprise. Once a game, perhaps, to leave my opponent guessing? Not only would this strategy help preserve my body; it would also ensure that my new "weapon" -- which I developed out of necessity -- would not go to waste.

The second reason that I'm interested in the morality of underhand serving is that I teach business ethics to college students and professionals. In business, this form of question -- "It's legal, but is it ethical?" -- comes up all the time. It may well be the defining question of 21st century capitalism, in which the actions of the powerful affect the well-being of the powerless, income inequality is growing, and cross-cultural value systems clash for supremacy - as business leaders and regulators grapple with the extent to which their ethical obligations should constrain their economic activities. Here's a simple example to illustrate: In certain industries, there are no rules or regulations against giving lavish gifts, such as luxury box tickets at a professional tennis tournament, to a potential client. However, if the gift actually influences the client's decision to award business to you, they have made their decision for the wrong reasons -- an outcome you have corruptly facilitated and for which you may even be rewarded. Legal, but hardly ethical. In recent years, this form of question has also arisen with regard to whether businesses should share customer records with government surveillance programs, whether to contract with host country manufacturers whose employee health and safety practices do not meet home country standards, how aggressively to promote adjustable-rate mortgages, and so on. Of course, I am expected to discourage my students from doing not only that which is illegal but also that which is questionably ethical. But as these examples suggest, that's easier said than done. If I use my underhand serve, will I be setting a bad example?

One distinction business ethicists make to analyze this kind of question is between descriptive ethics (generally accepted norms of behavior, or what people do) and prescriptive ethics (normative behavior, or what people should do). As a moral community, we are deficient when what is normal falls short of what is normative, or when we merely comply with required behaviors without aspiring to desired behaviors. To build on the aforementioned example, even though giving gifts to influence potential client decisions may not only be legal but also quite common, that doesn't make it right. Like scholars, laypersons also recognize a continuum of behaviors, from illegal to barely legal to legal to ethical. This is evidenced by the visual metaphors we employ in reference to the gap between what's legal and what's ethical: That gap is a "gray area"; ethics is a "higher bar" than legality; and we should be careful not to "cross the line" into illegal behavior. These metaphors have real analogs in tennis, of course. White lines demarcate the boundaries between in and out, and the net is a flimsy bar that a good shot has to clear. These limits are generally "black and white", as we are prone to visualize, whereas some players feel obliged to apologize for a net cord, and underhand serving is in that gray area. To try to clear up the blurry gray, I surveyed a few professional tennis coaches to get a feeling for descriptive norms around underhand serving. One laughed and said, predictably, "Well, it's legal, but your opponents will think you're cheating anyway." Another seemed more willing to "toe the line", saying, "Hey, you should do what you have to do to win." Referencing Chang's use of the underhand serve, one pro said that it was acceptable for him because he was so physically debilitated that he really had no choice if he didn't want to lose. Overall, the shared sentiment seemed to confirm the point with which we began: It's legal, but questionably ethical -- although that last comment characterized the ethically acceptable underhand serve as a kind of desperation measure. Unfortunately, desperation is where the slippery slope into unethical behavior often begins.

Those who think of underhand serves as a kind of legal cheating are essentially asserting that it really should be illegal. Law lags behind ethics, and although we don't (yet) have a rule for everything, we are ethically responsible for abiding by the so-called spirit of the law, not just its letter. That is why laws are passed after a raft of unethical behavior exploits a weak spot in the regulatory system. For a long time, trading on second-hand information from a loose network of business associates fell into the gray area of insider trading, but recently law enforcement officials have increasingly targeted this kind of behavior as not only unethical but illegal. There are more laws -- and more litigiousness -- in developed markets because the legal system has had more opportunity to catch up to creative exploitation of loopholes. So, the argument goes, unethical businesspeople will make a short-term profit doing unethical acts until those acts become illegal, whereas those looking for long-term gain will steer clear of the line. The problem with this argument in relation to underhand serving is that there is no loophole that underhand serving exploits. It's also not like doping in cycling, in which there was not a loophole in the rules but there was a loophole in enforcement. If the cyclists who have admitted to cheating can be believed, everyone had an equal opportunity to break the rules. Any player has the means to underhand serve in tennis, but doing so is out in the open -- "transparent", in business parlance -- and not against stated requirements. The rule is clear that the ball cannot bounce during the service motion, but it would be arbitrary, and difficult to enforce, to suggest that the point of contact must be above the shoulder. The rule-makers of tennis' regulatory bodies do not consider underhand serving even to be a candidate for a new prohibition.

Ethicists also distinguish between intentions and consequences. If you intentionally deceive your opponent, according to deontologists, you may already have committed a wrong; whereas if you lose the point anyway, according to utilitarians, no harm has been done. The deontologist's conclusion presupposes that there is a universal rule against deception -- in sports, business, and everywhere else. So, in the spirit of full disclosure, I must admit that I have been practicing how to begin the underhand motion with the same starting point as the overhand motion, so that my opponent cannot tell that an underhand serve is coming his way. This works when a big server like Ivo Karlovic senses his returning opponent has retreated so far behind the baseline that a drop serve might catch him off guard. Part of the very point of the stroke is that it augurs against transparency. It only works as a deception which seems, well, deceptive. A classic argument by Albert Z. Carr got around the deontologist's claim by exempting games -- like poker and business, and presumably, tennis -- from the ordinary rules of ethics. He argued that "business bluffing" was ethically acceptable -- for example, in negotiations -- because it was part of the "rules of the game" that all game-players should expect, as in poker. When I discuss his argument with my students today, however, I often emphasize the adverse impact that bluffing can have on stakeholders who are involuntarily affected by the game -- individual investors whose share values are adversely affected by mega-hedge fund managers shorting stock, for example, or even the natural environment that may be degraded as a powerless piece in a negotiation between a land developer and construction company. So, the conventional argument has become that voluntary game-players should look out for the ethical welfare of involuntary game-pieces who could be harmed by deceit out of ignorance or powerlessness. But that argument does not necessarily render deceit of game-players unethical. In fact, deceit is a celebrated element of many of tennis' greatest shots -- from Federer's famous "inside-out" forehand, which his opponents often can't tell he is going to hit to the opposite corner, to a surprise topspin lob that is "disguised" as a passing shot, to a drop shot that is meant to catch an opponent wrong-footed. If it is underhandedly wrong, it is so only if you're playing queen versus pawn (to throw another game into the metaphor), that is, an advanced player against a novice or unsuspecting child who has not read the ITF Rules.

Notably, the crowd cheered unabashedly after Chang, an underdog teenager acting like a mature warrior, won his critical point. One decade later at Roland Garros, the crowd booed teen-aged Martina Hingis, the odds-makers' choice who was acting like a petulant brat, when she tried it twice against an almost-retired Steffi Graf. Both Chang and Hingis ended up in different kinds of tears, while the crowd's fickle treatment of them suggests also that ethical sentiment about underhand serving is unsettled, rationally inconsistent, and, more than anything, emotionally motivated. Without a compelling rational case against underhand serving, I'm inclined to test my normative ethical conclusion empirically on-court. However, if underhand serving causes me to lose more points than it helps me to win -- the test will be short-lived, which will render my ethical conclusion irrelevant on-court, nothing but an intellectual game.

Off-court, however, there remain lessons to be learned. First, analogies between games and life, whether poker or tennis, are imperfect. Playing with real lives is not a game. We're only starting to come to terms with this point as we punish guys who risk their character, reputation, the integrity of the game, and even their own lives doing underhanded things, like taking performance-enhancing drugs, to play games better. Second, analogies between sports and business are also imperfect, but business strategies that are predicated on staying a step ahead of regulatory action have a lot in common with athletes who would presume to outsmart drug testing regimes. When they fail, they not only compromise their own viability, but they also destroy confidence in the system. Finally, because we live in this system full of mistrust, we are required to do awkward things like vouch for our own trustworthiness, so before I sign off, let me note: Research standards require me to disclose that I have a material interest (i.e., winning) in reaching my conclusion that underhand serving is ethical, since I stand to gain from it, performance-wise. So watch out, guys -- you've been forewarned.