If you've ever watched a game the Metrodome, Arlington Stadium or Riverfront Stadium, you may better understand the charms of Memorial Stadium, its beautiful grass, strange bounces and metal seats.

You may also understand why the city of Baltimore and the Oriole want a new one. There are only 7,474 permium seats, there isn't much leg room and there is little parking. The Orioles say they can't survive in baseball's era of free agency without having luxury sky boxes to sell or 15,000 premium seats to have sold by April 1.

Maybe. All those things are true, but if Memorial Stadium is obsolete, there is something wonderful about obsolescene.

It sits between two of Baltimore's oldest, most estabished neighborhoods -- Ednor Gardens, just over the center-field fence, and Waverly, a couple of blocks away. The neighborhood setting gives the stadium a sense of tranquility that's impossible to find in Minneapolis, where the piped-in music makes the atmosphere a cross between an organ chamber and a disco.

The little men who serve as ushers are perhaps the friendliest in baseball -- unlike the wardens at Yankee Stadium -- and all the lower-level seats are close to the action.

Once you're settled in, of course, watching baseball is as much a personal art as the game itself, but here are a baker's dozen tips from one observer:

1. Get there for batting practice. (For a 7:35 p.m. game, the Orioles hit between 5:10 and 6:15, and the visiting team from about 6:20 to 7. For an 8:05 game the normal starting time on Fridays everything happens a half hour later. The stadium gates open 1 1/2 hours before game time, except on major promotion nights when a big crowd is expected; then the gates open two hours before.)

You can learn a lot about the players by watching batting practice. Last summer in Oakland. Mike Boddicker made one of the most important discoveries of his career when he saw the A's getting only curveballs thrown to them.

That told Boddicker they'd be waiting for curveballs this night, and early in the game, he discovered they were. He chaned to a fastball and threw an eight-hit complete game.

Some tips: Eddie Murray hates batting practice, and his work habits reflect it. However, he does enjoy throwing balls of tape at teammates and reporters, eating sunflower seeds and swinging at pitches in the dirt.

Just before each group finishes its round inthe cage, the players take what is called a Thunder Round, the goal being to hit the ball out of the park. Mike Young is the Thunder Round champion.

2. Watch coach Frank Robinson during batting practice. He prides himself on being able to hit grounders past Oriole third basemen, and the more balls he hits, the harder he hits them. He and Floyd Rayford have a good rivalry.

3. During batting practice, watch Oriole pitches work on their tans. Jim Palmer believed that wearing a cap contributed to his hair falling out, so he stopped wearing one while shagging balls in the outfield. Other pitchers followed, and it has become an Oriole tradition. In spring training, catcher Rick Dempsey didn't wear a cap in the outfield one day and said, ''Now, I know what happened to our pitching. The sun fried their brains.''

4. After batting practice comes what is basically a ball-handling drill called ''infield.'' Here's where you get a chance to see the acrobatic ease and finesse with which the players handle grounders and pivot plays. That period runs roughly 7 to 7:20 (7:30 to 7:50 for Friday night games), with the O's on the field second.

5. Once the game begins, watch where Orioles manager Earl Weaver stands, sits and smokes his cigarettes. If he relies on statistics more than any other manager, he also relies on superstitions. If he used red ink filing out a lineup card Tuesday, and the Orioles win, he will use red ink each day until the Orioles lose.

In the dugout, he is even worse. He will look for a lucky spot in the runway, on the bench, on the steps. If someone hits a home run when he's standing in a certain spot, he may not move for hours.

6. Watch Weaver's smoking habits. The closer the game, the more he smokes, and in particularly tight situations, he'll disappear into the runway needing about two puffs to finish a cigarette. (He smokes Raleigh's and, yes, saves the coupons. "I once saved enough and got Al Bumbry," he said.)

7. Avoid the concession-stand crab cakes. They're doughy, and more often that not, cold. Three National Premiums may not wash one down.

8. Don't avoid the Polish suasage hot dogs. Hot, saucy and juicy, they're top of the line.

9. Watch for action in the Orioles' bullpen. Not necessarily pitching action, either. Before Sammy Stewart was traded to the Boston Red Sox last winter, he routinely did Michael Jackson moonwalks, played invisible guitars and performed various pantomime routines. He's no longer around, but there still may be Rick Dempsey, who knows how to dance, and coach Elrod Hendricks, who sometimes sends hitters vague signals about what they may be doing wrong.

10. Do buy an Orioles media guide. It's $5, but it's 224 pages and one of the best anywhere. Where else can you find out that the Orioles didn't have a Gold Glove winner for only the third time in 26 seasons in 1985; that Wes Stock is the only Orioles pitcher to win two games in one day; that lighthitting Alan Wiggins hit .380 with men on second or third last season; that the 32 complete games in 1985 were the fewest by an Oriole staff since 1967?

11. Do not leave early. Orioles Magic is not just an advertising slogan. In the last decade, some of the Orioles' finest moments have come in the ninth innings after. Even in the bad 1985 season, the Orioles won eight games in sudden-death situations, inluding a May weekend when Fred Lynn won back-to-back games with ninth-inning homers.

12. It's not widely advertised, but some very good seats are usually avaibable about an hour or less before game time. These are the seats season-ticket holders exchange, and you can buy them at either the ''West Lot'' or ''East Lot'' gates. A note of caution: Lines for these tickets are sometimes long, and their availability depends upon the importance of the series getting tickets for the New York Yankees.

13. Take a shortcut. One good route is the Baltimore-Washington Parkway or I-95 into the city; then follow the signs to Martin Luther King Boulevard. Take MLK north to Howard Street. Left on Howard. Right on 25th Street. Left on Calvert Street. Right on 33rd Street to the stadium.

Going home, you're better off taking Maryland Avenue instead of St. Paul Street. Maryland Avenue is two blocks west of St. Paul.