New York Mets manager Davey Johnson gnawed on a wad of chewing tobacco, contemplating what radio announcer Bob Murphy aptly described as "one of those war-of-nerve situations that a manager gets paid to manage for." One out in the bottom of the seventh on this late-June afternoon, and the Mets had already blown an early 6-I lead to the Phillies before rallying to tie against Philadelphia reliever Bill Campbell. Now they had the go-ahead run at second, and the crowd at Shea Stadium was screaming for more. With first base open and first place at stake, all eyes turned to the home dugout to see whom Johnson would send out to hit for his pitcher.

"It'll be interesting to watch Davey's move here," noted Murphy from his pressbox perch, thinking aloud as any knowledgeable fan might. "He's got [right-handed slugger] George Foster and [left-handed pinch-hitting wizard] Rusty Staub both in reserve, but Rusty hasn't had much success against Campbell, even though he's one of the better pinch-hitters in the league. Foster's the obvious homerun threat, but the Phillies could always walk him to pitch to Staub. You can almost hear the wheels turning in both dugouts." Or the faint hum of computers.

Down on the Phillies' bench, manager Paul Owens was shuffling through lineup cards and considering a variety of possibilities: If Foster came in and was pitched to, it meant the potential winning run was at the plate -- with a game-breaker in the batter's box; Staub was the better clutch hitter, but at .067 lifetime against Campbell, he was no historical favorite to do heavy damage. Either guy could be walked to get to the other, setting up the double play. And Owens had Jim Kern, another short reliever, warming up in the bullpen. Johnson, on the other hand, was squinting at the mound and pondering the inadequacy of certain statistics. Roughly 60 feet down the stadium tunnel, or about the distance from the pitcher's mound to home plate, sat his IBM PC/XT microcomputer, Johnson's so-called sixth coach, which he consults before each game.

One for fifteen, yeah, he thought, trying to visualize his printout on Staub vs. Campbell, but how many of those balls were hit hard? Where did they go, infield or outfield, right side or left side? Were there men on base? How many outs? Late innings or early innings? Night games or day games? Home or away? Was Staub playing hurt? Would Owens risk walking Foster:' Would Campbell have to pitch Staub too carefully? Is Rusty loose? Is he due today? Having no terminal to consult for an immediate answer, Johnson scratched his head and motioned for the right-hander.

Foster took four wide ones and trotted down to first. As the crowd buzzed with anticipation, the portly, 40-year-old Staub tossed aside his batting donut and settled into a semicrouch at the plate. Campbell glared in for the sign. "I regarded it," Johnson would later say of this second-guesser's smorgasbord, "as your classic 'unfavorable chance deviation.' " Staub regarded Campbell's first pitch as a meathigh fastball, and roped it to right for the game-winning RBI.

Hardball hunch meets personnel pool meets disk drive, produces line drive: "The media has a lot of fun with this computer thing," sighed Staub, child of another baseball era, in the warm Shea twilight of next day's batting practice, "but I think you can make too much of statistics. There's no substitute for baseball sense. David's no slave to the computer. Sometimes, I swear, I have no idea what he's doing."

What Johnson is doing is taking a small but highly visible business with only one tangible product to sell -- the performance of its people -- and managing it, using that most tangible of new business tools, the computer. Once the very symbol of baseball ineptness, the Mets have assumed an aura of slick proficiency by becoming the latest professional sports franchise to experiment with the computer as a major strategic weapon. Johnson's challenge: to integrate what the computer can tell him with what he already knows about the business of winning baseball games. Against a backdrop of pennant pandemonium, this is management at a technological crossroads.

In the beginning there was NFL football, with its high-tech approach to playerscouting and play-charting. Soon, the use of small but powerful computers entered the arenas of thoroughbred racing, international yacht racing, big-time road racing, professional basketball, and a host of other sporting industries. But baseball, perhaps the most number-driven of any major sport ("baseball," avers Toronto Blue Jays executive Paul Beeston, another recent computer convert, "is one big statistic"), has been slow, if not reluctant, to adapt. It is, after all, an industry dominated, from the front office to the playing field, by thinkers from baseball's past. The tradition of baseball, its shared knowledge and its shared strategy, is fundamentally an oral tradition, handed down from coach to player and league to league over succeeding generations. Pitch Schmidt up and in with men on base so he can't get his arms extended, but don 't try it at Wrigley Field, the "book" might say. Get anything you can off Carlton early because he gets stronger after the third. The wise manager filters baseball's folklore through knowledge of his own personnel and the vagaries of game conditions. Numbers are indicators, but only indicators.

Yet numbers, when properly assimilated, are also baseball's secret weapon. Johnson remains coy about exactly what figures he wants to manipulate ("it's no secret that I keep a history of all hitting and pitching matchups," he asserts, "but I don't want to be too specific about the rest of it, because a lot of people don't understand its interpretation or importance"), and he admits that he began his off-season programming with a thin database ("the Mets didn't keep shit; it was ludicrous"). But since decisions like defensive positioning and pitch selection are usually made by the players on the field, based on their own instincts and experience, it appears that Johnson is primarily interested in using the computer to govern the rhythm of lineups and pitching rotations over the course of a series or a season, not inning by inning: using it for the kind of long-term strategy that usually is served better by analysis than by hunch.

Harry O'Shaughnessey, a Mets vicepresident, says, "We're recording data more at the box-score level for now; we're not looking for a system we can take into the dugout with us." To which Johnson adds, "At one point yes you'll see a terminal in the dugout, because nobody's memory's perfect, and there are times in a game when I'll want to go back [to my office] and study something. But that day is a long way off. I don't even take the machine on the road with me. I have to do my studying of printouts before and after ballgames."

While the Mets' field general may occasionally leave his own players wondering what he is up to, there is no mystery to his own fascination with the computer and its power to ingest and refine data. Johnson, surely the first manager in big-league history to grace the cover of his team's media guide sitting at a PC screen instead of berating an umpire, took an introductory computer course about 18 years ago and has expanded his studies ever since. A feisty second baseman with a college background in math and probability theory, he tutored under Baltimore Orioles manager Earl Weaver, baseball's contemporary Einstein of statistics and platooning, and wrote his first baseball program for Weaver. Called "The Optimization of the Orioles Lineup," the program challenged Weaver's assumptions about batting-order run production and recommended, inter alia, that Johnson himself bat second rather than sixth. (Earl smiled, and threw the report in the trash can.) Once his playing days were over, Johnson eventually took over a pair of Mets' farm teams and managed them to two pennants -- helped by a software program of his own design. Finally, after a dismal sixth-place showing in 1983, the Mets promoted him to the parent club, and Johnson convinced them to let him bring along his computer, too.

"We'd already been approached by a number of companies marketing sports-related software programs," says general manager Frank Cashen, "but to be quite honest with you, we weren't too interested. What most of these companies are trying to sell is really software programming they've designed themselves, not something that's tailored in detail for any individual team."

"The key thing," adds O'Shaughnessey, "is that the data produced by most of these programs is not worth much unless you have a manager with both the knowledge and the desire to use it. We didn't hire Davey because he knew computers. We hired him because he knows baseball. But we were receptive to his using [a computer] if he worked out the system himself."

Both Cashen and O'Shaughnessey cite the lesson of the Oakland A's, a team that embraced the data-feed principle with such fervor that they had a microcomputer in the pressbox recording every pitch and every result, home or away, during the 1983 season. The A's junked the system and went back to cruder hand charts after a year, however. In curtailing their effort, Oakland blamed both operational costs and the difficulty of obtaining pertinent data on rival teams. Some of the Oakland players, however, had also brayed loudly about the spectre of impersonal hardware dictating highly subjective field decisions. The anxiety level seems lower in cities like Chicago (the White Sox) and Seattle, where PC programming is also in use, and no factor at all for franchises like Atlanta and Toronto, where the first move -- just this year -- has been to computerize minorleague scouting reports and other playerdevelopment data for draft-session expediency. But the Mets knew, as Johnson knew, that the presence of a PC in the manager's office was a potent symbol. Johnson knew because he grew up, like his star pinch-hitter, in another baseball era.

"Baseball people were shocked when I set the single season record for most home runs [43] by a second baseman, back in '73 with the Braves," Johnson says from the dugout bench as he watches his team take infield practice one June afternoon. "But nobody had really studied my history. They'd changed my hitting stroke in Baltimore to make me more of an opposite field hitter, but when I went back to my old aggressive style, I began to hit home runs. One season, I had 15 at the All-Star break, before I got hurt. If you look at what I did after that, and what I did when I played in Japan, it wasn't really surprising atall."

Johnson sends a stream of tobacco juice between his cleats. Players are still meandering out to the batting cage from the clubhouse, down the long corridor and past the door to Johnson's office, through which are visible both the PC and a plethora of charts with titles like "Best Way to Get Batter Out" and "Best Way to Get GroundBalls."

"You talk to the old school of baseball men about computers," he continues, "and you're talking in an area that's really foreign to them. They know that so-and-so hits so-and-so, or that this guy's a high fastball pitcher and this guy's a low breaking-ball hitter. What they don't know is that you can be much more finite than that. You can compute, say, the probability of scoring X amount of runs against Steve Carlton over 5 starts, or 50 starts, using one lineup, and then see how you can score an average of 35 more with another. Thirty-five extra runs against Steve Carlton, even spread out over a couple of years, can win you a pennant.

"Or," he says, "I might write a program for [Mets pitcher] Ron Darling, showing him the probability of a batter getting on base against him when his first pitch is a ball. Then I can show him similar numbers when the count runs to 2-0. Or when it's 01, or 0-2. That's where numbers are useful, and what the computer can do so well. If you can't apply the technology to your people, though, you'll only produce chaos and confusion. And you have to be consistent. In any management job, it's how you relate to what you're trying to accomplish, and I don't need the computer to explain my actions. I also don't need the computer to be a good baseball manager."

Darling, a former Yale University student, concurs. "Ever since I got up here [the majors], people have been telling me I think too much. That I should just pitch. So I don't pay much attention to Dave's computer. He's a good baseball man, the players like playing for him, and if the computer helps him, fine. I have to get Mike Schmidt out."

The question of PCs in the dugout and other revolutions in the grand old pastime have haunted a number of outside baseball experts ever since the great Oakland Experiment of '82. Bill James, the guru of armchair statisticians, suggests that a terminal by the bat rack would diminish the game's fan appeal by interposing a piece of alien hardware between the nuance of field strategy and the guy in the bleachers with his beer and his scorecard.

James, author of The Bill James Baseball Abstract 1984, adds, "I don't care how much you love that damn computer, it's still ballplayers who win ballgames for you. And in a business sense, baseball's practices haven't advanced all that much anyway. It amazes me how many professional teams exhibit no judgment whatsoever when it comes to evaluating their onfield talent. There's nothing you can feed into a computer, for instance, that will prove to you that [Boston Red Sox first baseman] Dave Stapleton doesn't know how to play big-league baseball, but he doesn't. That's an organizational problem, not a data-processing problem."

Frank Cashen stared down from the pressbox at the ballfield below. All seemed serenity and order. The Mets had the early lead on Montreal, I-0, and out on the mound one of his young pitching aces, Dwight Gooden, was blowing away Les Expos with a slingshot fastball and a kneelocking curve. Cashen, an affable emissary from a distant baseball generation, talked about modern times.

"When Davey played for us at Baltimore," he said, "he used to come into my office with a bunch of computer printouts to negotiate his salary. I had no idea what he was talking about. You have to understand that in those days anyone who even knew what a computer was thought it was this cumbersome thing that took up a whole room in a factory somewhere. Now fourth graders know more about these machines than some of the kids coming out of college. That's bound to have an effect on those of us who've been around the game a long time and are considerably behind in technology."

He paused as Pete Rose measured a Gooden heater and drove it off the pitcher's shinbone for a sharp single to right. Tying run aboard.

"Probably the biggest advance we're seeing now," he continued, "is in how we get our scouting reports. These things are still very subjective, but when you have to keep track of literally thousands of ballplayers at both the professional and the amateur level -- when 26 teams are drafting 40 deep each -- being able to instantly pull, say, the name of every left-handed college pitcher and his stats is enormously useful. If you keep all that information on file cards and lose a card, you've effectively losta player."

Andre Dawson took a strike at the knees as Rose danced off first.

"I was talking to Bill Stoneman, the assistant to the president of the Expos, just today. Stoneman was a pitcher who went into banking and learned a lot about data processing. He thinks, and I agree with him, that a lot of computer work will soon be focused on player arbitration and salaries, and that will have an impact, too."

Ball two to Dawson, a dangerous hitter when ahead of the count.

"What I really want to do," Cashen sighed, "is take six months off and study computers myself. Because otherwise I'm headed into the next century not really understanding a lot of the things that are going on at the present time. I marvel at what Davey does, but I marvel at what some of these young players are capable of doing, too."

Dawson, no longer a youngster himself, caught a letter-high Gooden fastball and drove it over the right-field wall, somewhere in the general direction of the Queens Botanical Gardens. Cashen blanched.

"Not the high fastball," he moaned. "Not to Dawson." Somewhere several floors below him was a database that no doubt agreed.