The true test for the Minnesota Twins will come after the all-star break when they play 11 consecutive games against the Toronto Blue Jays and the New York Yankees. Presumably, they'll still be in first place then and, presumably, the California Angels will be about to make a charge.

If the Twins fold, a lot of people wouldn't be surprised. If they don't, one of baseball's best stories in 1987 will get even better.

Just about all the other 25 teams spent last winter looking for pitching, and not too many people blinked when the Twins signed free agent Juan Berenguer.

Six months later, that looks like one of the steals of the winter. Not only has Berenguer gone 5-0 with a 2.93 earned run average, he already has pitched 67 2/3 innings with 27 walks and 78 strikeouts. Berenguer, Keith Atherton and George Frazier have a combined 14-3 record and have been effective enough that Manager Tom Kelly has been able to keep from burning out short man Jeff Reardon.

To show that pitching help sometimes comes from unexpected places, Berenguer was the biggest, but not the only bargain for the Twins. Atherton came from Oakland for pitcher Eric Broersma, and Frazier was a bonus in a trade that allowed the Twins to dump erratic Ron Davis on the Cubs.

As the weekend began, a lot of people still didn't know what to make of them, especially after they ran off a 15-3 streak against Milwaukee, Kansas City and three losing teams. Still, as the weekend began, they were 13 games above .500 for the first time since 1979.

The Twins are at least surviving, which is more than can be said for the Kansas City Royals. Since fifth starter Bud Black went down with an injury, the Royals have had to throw Bob Stoddard in for a start and Rick Anderson in for another. They've been outscored by 19-1 in those games and will be forced to use Anderson against the Twins this week.Bo Jackson Benched

Meanwhile, Bo Jackson has gone to the bench after striking out 28 times in 15 games. He's another reason the Royals have slid from a five-game lead in the AL West to a five-game deficit in a month . . . The Texas Rangers came off a 5-2 West Coast trip, but, just when they thought they might make a move, they were swept by the Angels in Texas. In that series, all the Rangers' problems hit them square in the face again. They made eight errors, they went two for 27 with runners in scoring position and their pitchers started six innings with walks. All six batters scored.

One of the Rangers' lone bright spots is reliever Dale Mohorcic. His nine-year minor league career ended last year and, in 22 games this year, he has allowed five earned runs and four walks in 33 2/3 innings. That figures to a 1.34 ERA, and he has blown only two of 11 save chances . . . Best bad matchup: Texas' Charlie Hough vs. the California Angels. He has a 2.86 career ERA against them but only a 5-8 record . . .

Ron Darling still hasn't won since April 22, but this week he gave the New York Mets hope that his troubles are behind him. He went eight innings and allowed four earned runs in a loss to the Chicago Cubs, but more important was his style. He dropped the forkball and offspeed stuff and went back to being a fastball-curveball pitcher. With Dwight Gooden pitching well and Sid Fernandez at least dependable, the Mets may yet make a run at the St. Louis Cardinals . . .

Some of the Chicago White Sox thought it was a joke this spring when new general manager Larry Himes sent out a 32-page dress code memo. They found out it wasn't after a 13-3 victory over Seattle this week. Himes walked into the clubhouse and fined three players for not wearing socks. Ivan Calderon was slapped for $200 because it was his second offense, Jose DeLeon and Scott Nielsen $100 apiece.

Himes is showing a lot of guts for a man who has made one bad move after another since he was hired to replace Hawk Harrelson. His new outfielder, Gary Redus, is hitting .223, 35 points below his career average. Infielder Donnie Hill is hitting .190, 83 points below his career average. And catcher Ron Karkovice has five hits and 35 strikeouts in 77 at-bats. There isn't one Chicago player among the top eight American League all-star vote-getters at any position.Chicago's Reluctant Pitcher

Earlier this year, White Sox minor league outfielder Dave Cochrane bragged about how hard he could throw. He answered a dare by getting on a mound and throwing 86 mph. That so impressed Himes that he has decided to make Cochrane a pitcher even though he's leading the Class AAA Hawaii team in homers and RBI. He has recently been clocked at 88 mph, but says he'd like to move back to the outfield . . . Milwaukee Manager Tom Trebelhorn called Teddy Higuera and his catchers in for a talk this week after Higuera blamed his 1-7 slump on no longer having veteran catcher Charlie Moore around . . .

Toronto reliever Mark Eichhorn has allowed six homers in his last 10 appearances and says his motion has gotten completely messed up. His trouble started when the Blue Jays wanted him to speed up his delivery to slow down base runners. Now they've told him to forget the base runners and pitch the way he once did. The Blue Jays also don't know what to make of George Bell's puzzling slump at home. He's having an incredible season on the road, hitting .360 with 19 homers and 45 RBI. But at Exhibition Stadium, he's batting .233 with six homers and 20 RBI . . .

When the Boston Red Sox brought rookie center fielder Ellis Burks to the majors, Manager John McNamara said, "Hopefully, this will be the beginning of a change in the Red Sox, and I hope I'm around to see it." Since then, the Red Sox have given two other rookies, Todd Benzinger and Mike Greenwell, regular jobs, moved Dwight Evans to first base and taken a job away from Bill Buckner. The result is a not-so-subtle change in style. Burks already has 11 steals; Marty Barrett's 15 led the Red Sox last season. They've stolen 33 bases, eight fewer than they had all last year.

Burks' 12 homers are the most for a Boston rookie since Jim Rice hit 22 and Fred Lynn 21 in 1975 . . .

Phil and Joe Niekro say they get so many requests about how to throw the knuckleball that they'll make a how-to-do-it video this winter . . . Houston left-hander Jim Deshaies celebrated his 27th birthday by riding an elephant at the San Diego zoo . . . Former Yankee Charles Hudson celebrated his return to the minors by allowing seven earned runs and 12 hits in four innings for Columbus this week . . .

San Francisco Manager Roger Craig has used 10 leadoff hitters and 58 lineups in 68 games . . . Has Andre Dawson been valuable to the Cubs? Thirteen of his 20 homers have come in the sixth inning or later.