Baltimore — Until you've trudged through a valley of disappointment the way Philadelphia's John Denny has, the summit of achievement never looks so good. In his own concise way, Denny, a saddened 6-13 pitcher in 1982, said as much when he remarked, ''What a difference a year can make,'' after winning the World Series opener here 2-1.
That summed up his feelings upon out-duelling Baltimore's Scott McGregor in one of the greatest displays of control pitching ever witnessed in baseball's showcase event. Neither walked a batter, nor did any of the three relievers who saw action - a rarity in any game and something that's only occurred five other times in Series' history, and not since a 1967 game between St. Louis and Boston.
Denny, making his World Series debut, had to play the part of a postman - neither rain, nor a first inning Oriole homer, nor potential distractions could keep him from his appointed task.
The rain began before the first delivery and ended long after the last out, but was never heavy enough for the umpires to call a halt. Mud began to clog his cleats in the late innings, but Denny had pitched in almost identical conditions against Pittsburgh at the end of the regular season and found the weather no problem.
He actually seemed to get stronger, mixing a good fastball and curve effectively until Manager Paul Owens lifted him for reliever Al Holland in the eighth.
The only real damage was inflicted in the first inning, when Jim Dwyer, only the second Oriole batter, deposited a home run over the right field fence.
For a while that looked like it might be the only run in this oddly quiet game, which saw both pitchers turn the basepaths into a virtual ghost town. And that certainly couldn't have been much comfort to Denny, who could have sued his teammates for nonsupport several times this year. Though his 19 victories were both a personal high and the top total in the National League this season, John should have been a 20-game-winner - as seen by the fact that in his six losses the Phillies scored just seven runs.
Eventually, however, the Phils countered with two solo homers of their own, Joe Morgan's in the sixth and the winner by Garry Maddox in the eighth.
Denny's record indicated he could handcuff the Orioles; in three seasons at Cleveland he compiled a 3-1 mark and a l.43 earned-run average against them.
Since entering the majors with St. Louis in 1975, the 6 ft. 3 in. Denny has been brilliant in spots. In his second season, he became at 23 one of the youngest National League pitchers to win an earned run average crown, giving up just 2.52 per game. In 1978 he won 14 games, and he finished out the 1981 campaign with 34 and 2/3 scoreless innings for Cleveland.
The roller coaster dipped to its lowest point last year, when he missed a month with shoulder problems, had a 4.87 ERA, and never got on track. With Denny's market value down, Philadelphia dealt three little known players to the Indians for John late last season.
The gamble has paid a handsome dividend. Denny has emerged as the cornerstone of a rebuilt pitching staff and is almost a cinch for Comeback Player of the Year with his 19 victories and a 2.37 ERA, second only to Atlee Hammaker's 2.25 with San Francisco. And when the Phillies needed him most, John turned in his best efforts, winning six straight games in September to earn National League Pitcher of the Month honors.
So what's made the difference?
''That's hard to answer,'' he says. ''I just know I've grown a lot in the last year. The thing I've accomplished this year is consistency, which is what separates it from other years.''
''Part of it just comes from playing with guys like Joe Morgan, Pete Rose, Steve Carlton, and Mike Schmidt, who have so much experience.''
Denny's consistency has also increased as he's lessened his reliance on pure power and jacked up his concentration. In the Series opener, for example, he wanted to tip his cap to President Reagan when the Chief Executive was introduced early in the game. But instead he decided to prepare himself mentally for the next batter. He also delayed his trip to the mound during singer John Denver's live performance of ''Country Boy,'' a song that has become a seventh inning tradition at Memorial Stadium. He didn't want anything throwing him off.
Tuesday's effort, of course, doesn't leave much room for an encore, but when John takes to the hill again, he will have someone special looking on - his father.
In the last five years, John had fallen out of touch with his dad, who's remarried and now lives in Australia. He's arranged for a bridge-the-gap reunion , however, in which his father will fly in for this weekend's games, to be played in Philadelphia as the ''I-95 Series'' moves up the road.