Maybe the home run boom of 1985-86-87 is not just caused by rabbit balls or weightlifting batters or a generation of crumbum pitchers. Perhaps it's also part of baseball's oldest battle of wits -- the war between pitchers and hitters to figure out better ways to play the game. Maybe, just maybe, what we're seeing is a period when hitters have gotten one big theoretical jump ahead.

Let's pose another possibility, too. Perhaps the eruption of beanballs and brawls this year is not a measure of bad temper and low character. Maybe it's basically an inevitable byproduct of the same trends in pitching and hitting that have brought us so many home runs. Our argument takes a while. Conclusions come at the end.

Baseball has always been a sport of cycles. Candy Cummings came up with a curveball, so John McGraw figured out the hit-and-run. We'll see your thick-handled bat with a spitball and raise you a chaw of slippery elm.

Almost as soon as Babe Ruth learned to hold the bat down at the knob, Carl Hubbell perfected the screwball. So what if Ernie Banks proved you could hit the long ball by whipping a 32-ounce bat? Jim Bunning was busy working on his slider. When we thought nothing could be more dastardly than a scuffball, hitters figured out how to cork their bats. The pitchers formed a "union," exchanging information about hitters across team lines. So, batters decided to study films of their swings and collaborate on theories about technique.

What's up in the '80s? Why do so many hitters seem so confident these days, so sure what they're trying to do meshes nicely with the weaknesses of the generation of pitchers they're facing?

Over the last 20 years, baseball has seen more and more pitchers who live by the sinker and slider, rather than the fastball and curve. It takes a great arm, and a young one, to throw directly overhand at more than 90 miles an hour or make a ball drop a foot. On the other hand, a less gifted pitcher, or an aging one who has started to drop down to three-quarter arm, can master a pitch that snaps six inches sideways or drops a bit an the end. It's an easier trick.

Also, since the days of Juan Marichal and Bob Gibson, it's been gospel to preach that "the low-outside corner is the way to the Hall of Fame" and "keep the ball down."

The vogue of "the high hard one" and the glamor of "getting in his kitchen" -- i.e., throwing fastballs up and in -- has waned. That's not to say Nolan Ryan never existed. We're just talking about trends, not laws.

Gradually, the knees and the outside corner became the target of most "quality" pitches. Anything up or in that got hit was dismissed as a mistake, while any homer off a low or outside pitch was excused as "a pitcher's pitch" that somehow ended up traveling 400 feet. Pitchers begged umpires to give them low or outside strikes; so that's what they got. The strike above the belt or in on the belt disappeared. Even the American League's switch to inside chest protectors for umpires -- allowing a better view of low pitches -- tended to move the strike zone low and away, where pitchers thought they wanted it.

Another factor contributed to this infatuation with sinkers, sliders, "cut fastballs," low change-ups and (the latest craze) the split-finger fastball. Fewer and fewer pitchers could throw a true big league fastball.

"I watched the College World Series this year and saw one guy with an honest fastball," said Dave Righetti of the Yankees with disgust to Ron Guidry. "They all want to throw forkballs. Mike Loynd comes out of college -- 22 years old (and 6-foot-4) -- and all he throws on 2-0 is curves. They've forgotten to work on the fastball."

"It's all changed. You just don't see the real strong arms anymore," agreed Guidry. "{Greg} Swindell {of Cleveland} is one of the few young guys who really lets it loose."

When a Roger Clemens, Dwight Gooden or Bret Saberhagen arrrives with real 95-mph heat, he blows the league away. No wonder Ryan, in his dotage, still comes as a shock to hitters' systems. He's not what he was, but he's more than they've ever seen.

The fastball has gone the way of Little League and the aluminum bat. For years now kids have grown up playing in leagues rather than cooking up kids' games. "No wonder nobody can throw hard. Mom comes in the station wagon and the game's over. We played from sunup to sundown. You develop arm strength as a kid and you do it by throwing the ball hard a zillion times," said Yankees coach Stump Merrill.

At the high school and college level, the aluminum bat is ubiquitous. Try jamming a hitter who has a light, unbreakable stick in his hands. It just doesn't work the way it did for a century. Experience teaches developing pitchers not to challenge hitters up and in.

During all this time, have hitters been fast asleep? No way. "They've all been listening to {the late} Charlie Lau and {Boston coach} Walt Hriniak," said Righetti. "They stand off the plate, look for the outside pitch and dive in. They drive the ball to all fields. Every good hitter now is a low-ball hitter."

"Look at the big young guys like Mark McGwire, Jose Canseco or George Bell," said Guidry. "They lift weights. They want the ball down or away so they can extend their arms and generate power. They don't care whether they hit it over the center field fence or to the opposite field."

"The only way to get them out is with good fastballs above the belt or in, so you tie them up," said Righetti. "You used to see four or five guys in every lineup who turned on the ball to pull it or put their foot in the bucket. Now, almost nobody. Everybody charges the plate."

Yankees slugger Don Mattingly agrees completely. "Almost every good pitcher these days works inside first or up-and-in. You go in to set up the pitch away," he said. "But there aren't many pitchers around who can do it."

Pitchers see the problem, at last. The pendulum has swung -- at them. A world of Mike Schmidts and Dale Murphys, Andre Dawsons and Jesse Barfields couldn't care less about pulling every pitch or waiting for the "high hanger" to clobber. They lust after the low sinker or the slider away -- as long as it's not perfectly placed. That's when they can really unlimber. Lau started off teaching the purity of line-drive singles, but his disciples, from George Brett to Dave Winfield, quickly learned how to elevate those liners a few degrees and start driving Jaguars and Porsches.

Nowadays, the place to aim is inside or up and the place to miss is up and in. If a hitter has to slip a vertebra getting out of the way of a pitch that only misses the plate by six inches, whose fault is that, say the pitchers. What business does he have diving into the plate, taking away the outside corner -- the pitcher's half of the plate. It's no accident that every team Lau coached had a sudden increase in hit batters and brawls. His theories reversed generations of baseball territoriality. A price had to be paid.

Now, however, almost every team is a Lau team. And baseball finds itself in a strange, exciting home run-filled, yet distinctly dangerous and barely explored new place.