Manager Chuck Tanner of the Pittsburg Pirates feels there is a trend developing in major league baseball away from conventional pitching methods as far as setting up a starting staff is concerned. ''With so many good hitters on every team, it's almost impossible today to find starters who can go the distance,'' Tanner told me. ''The result is that more and more teams are building from their bullpens back, relying on relief specialists they can call on as early as the fifth or sixth inning. If you don't have at least one strong middle-inning and two strong late-inning stoppers in your bullpen, you can probably forget about being a contender.
''Managers are also reacting more today to what I call situation baseball, especially when it's late in a game and their team's lead is only one or two runs,'' Tanner explained. ''For example, suppose you've got a finesse pitcher going for you and you suddenly find yourself in a position where you need a strikeout. Since you already know that the chance of getting that kind of performance from your starter is extremely low, you reach into your bullpen for someone who can really fire the ball.
''That's one of the reasons why the Pirates expect to stay in the division race all year - because of the bullpen. I've got a reliever who can strike people out in Don Robinson; one who can get opponents to hit the double-play ball in Kent Tekulve; and one who won't walk anyone in Lee Tunnell.
Probably the most headline-grabbing pitcher Tanner ever managed, he says, was the legendary Bo Belinsky, who won only 28 big league games but whose off-the-field activities made him better known than most 200-game winners. Belinsky pitched for Tanner in 1969, while Chuck was a minor league manager in Hawaii.
''Bo was street smart and never missed an angle in his life,'' Chuck explained. ''In 1962, after pitching a no-hitter for the California Angels against the Baltimore Orioles, Belinsky was promised a $3,500 bonus by Angels' General Manager Fred Haney. Bo, who had been eyeing a used red Cadillac convertible, couldn't wait to buy the car, except that he didn't have any money. Well, would you believe that he talked that car dealer into accepting the baseball he used to throw his no-hitter as a down payment? It might also have helped, of course, that Belinsky had actress Mamie Van Doren along with him.'' Cubs patch roster
From manager Jim Frey of the Chicago Cubs on his team's early season trade with Philadelphia that netted outfielders Gary Matthews and Bob Dernier. ''Let's face it, we didn't have a lot of range out there until these two showed up. While we do have a rookie named Henry Cotto, who can fly and looks as though he has a future in center field, we weren't really sure at this point whether he could handle big league pitching on a daily basis.''
The trade has enabled the Cubs to move hard-hitting Leon Durham to first base and still leave Frey with so many outfielders he hardly knows what to do. Matthews has become a fixture in left field and currently ranks among the league batting leaders with a .372 average. Mel Hall, a frequently spectacular defensive performer who played center last year but is being platooned in right this season, is also off to a good start at the plate. Meanwhile Cotto and Dernier are getting some playing time along with holdovers Keith Moreland and Gary Woods as Frey tries to sort things out in the early going.
''Actually, the thing Dallas Green (Chicago's general manager) and I talked about most during the off season was getting two established pitchers, one right- handed, the other left, who could start for us,'' Frey said. ''Well, we did get a pretty good right-hander from Montreal in Scott Sanderson, but we still haven't been able to land the left-hander we wanted. However, any way we play it now we've got several former regulars on our bench who could be traded to improve our pitching staff.''
Since Green and his former club, Philadelphia, began trading regularly in 1981, 14 ex-Phillies have joined the Cubs and vice versa. From around the majors
* In only his second official major league appearance since 1982, David Palmer pitched a rain-shortened, five-inning perfect game for the Montreal Expos. By handcuffing the St. Louis Cardinals on 57 pitches, only one of which was hit out of the infield, Palmer picked up a 4-0 victory, gave the Expos a doubleheader sweep, and recorded the fourth shortened perfect game in history.
* Pitcher Phil Niekro, off to a fast start this year with the New York Yankees, could be baseball's next 300-game winner. Niekro started the current season with 268 major league victories.
* Boston Manager Ralph Houk says the Toronto Blue Jays should have won last year in the AL East and would have if their bullpen hadn't fallen apart late in the season. Houk may be right. During one week last August, the Blue Jays lost six games in which they either led or were tied entering the seventh inning.