In prehistoric times (before June 19, 1846, when Alexander Cartwright, baseball’s James Madison, its foremost constitutionalist, went to Hoboken and organized the first game under rules recognizable as the antecedents of modern baseball) Tocqueville wrote, “An American does not know how to converse, but he argues.” Small wonder litigation has become another national pastime. And baseball’s rules, together with the interpretive Case Book, are rich in lessons about the rule of law, beginning with the fact that a law often exists to promote virtue: “The umpire shall not direct the attention of any person to the presence in the batter’s box of an improper batter. This rule is designed to require constant vigilance by the players and managers of both teams.”

Sometimes the external restraint of law is required because the internal restraint of morality is missing. A sportswriter once said that professional baseball is “agreeably free of chivalry.” Which is why we have the infield fly rule. It begins with a definition: “An INFIELD FLY is a fair fly ball (not including a line drive nor an attempted bunt) which can be caught by an infielder with ordinary effort, when first and second, or first, second and third bases are occupied, before two are out.” When the umpire signals “infield fly,” the batter is out regardless of whether the ball is caught. This prevents infielders from letting the ball drop and getting a double play by making force outs on the runners who must assume the ball will be caught and therefore cannot stray far from their bases.

Before the infield fly rule, the defense could benefit undeservedly – that is, not from skill and speed but from tricky exploitation of a loophole in baseball’s laws. As was argued in 1975 in an analysis in the University of Pennsylvania Law Review, the infield fly rule’s codification of fair play would not have been necessary had the attitude of the amateur, the gentleman, the sportsman–“the British cricket spirit”–prevailed in America. But, then, this would not be America if we did not think that the primary point of playing is not exercise but victory. So there.

As a legal code becomes more complex, the need for Solomonic judgments becomes more common, as was demonstrated when George Brett of the Kansas City Royals hit the shot heard ‘round the law reviews. On July 24, 1983, in Yankee Stadium the Yankees were leading 4-3 with two outs in the top of the ninth when Brett, batting with a runner on, homered. Royals lead, 5-4, right? Not so fast. Yankees’ manager Billy Martin averred, and the umpires confirmed, that Brett’s bat had pine tar higher than the permissible 18 inches of handle. The rules say a batter is out when he hits “an illegally batted ball,” such as one hit by an illegal bat, such as a bat that does not conform to the rule about 18 inches of tar. The umpires said Brett was out and the game was over, a Yankee win. Brett went berserk and the controversy went to the American League’s president, Lee MacPhail.

He, according to an exegesis in the Fordham Law Review, practiced what Aristotle called epieikeia, putting himself in the legislator’s shoes, and applied the rule of lenity, which is that penal statutes are to be strictly construed against the government, which in this case means the umpires. Noting that the rule regarding illegal bats merely provides for banishing the bat from the game, MacPhail said it does not seem logical to add to the infraction the penalty of calling the batter out. Brett’s home run counted, and later in the season the last four outs of the game were completed. Royals 5, Yankees 4.

Baseball, like the Republic, is a republic “of laws, not men.” In theory. In fact, judges, and umpires, sometimes decide what the law is. Three years before being appointed to the Supreme Court, Charles Evans Hughes said, “We are under a Constitution, but the Constitution is what the judges say it is.” So is the strike zone, which the rule book has redefined to bring it into conformity with what umpires do.

The strike zone is what each umpire calls it, and that can vary with who is hitting (an umpire is particularly apt to call a pitch a ball if a great hitter like Tony Gwynn does not swing at it) or who is pitching (if a great pitcher like Greg Maddux comes close to the zone, the pitch is apt to be called a strike). But for years all umpires have been lowering the strike zone, rarely calling many strikes much above the batter’s belt.

Time was, the zone extended from the batter’s shoulders to his knees. Recently baseball’s rule-writers tried to enlarge the strike zone by shrinking it. They shrank the zone as the rule book defines it by further lowering the top of the zone. They did this in the hope of enticing umpires to enlarge their strike zone by calling higher strikes–strikes above the belt–in conformity with the new definition. By 1995 the top of the zone was defined as “the midpoint between the top of the shoulders and the top of the uniform pants” (which National League instructions to umpires defined, indelicately, as “the nipple line”) and the bottom of the zone was “at the top of the knees.” The 1996 rules reflect another surrender to umpires. The top of the zone remains the same but the bottom is “at the hollow beneath the kneecap.”

An architect said God is in the details. Umpires, like all judges, know the Devil is in the adjectives. Through them, law can be tantalizingly suggestive, as with the word “unwarranted” in this instruction to umpires: “A player guilty of an unwarranted attack on another player is subject to discipline . . .” Baseball’s rules are practical and mostly prosaic, but in the elaborations there are flashes of poetry. The instructions to umpires include seven lyrical words to live by: “Keep your eye everlastingly on the ball.” Some of us will do just that for the next seven months.