When he gets in the batter's box, Ken Singleton still picks up three pebbles to remind himself the pitcher must throw three great pitches to get him out while he only needs to pick one fat pitch to get a hit. Patience, he counsels.

The time comes, however, when even the most methodical and confident of men starts to fall prey to impatience, begins to allow anxiety to invade him.

These days, the veteran Baltimore Oriole seems as depressed as a great hitter who's in the third year of a batting slump. Because that's what he is.

When you're 36 years old and you've batted .235 in your previous 200 games--from the end of one season, through all of the next year and the beginning of a third--you wonder, just as everyone around you wonders, if it's The End.

If Singleton weren't so estimable, it would be easier to watch the drama of his current struggles. The next few months of his career will make a trenchant clinical study; here we have a man of keen analytical intelligence and great dedication pitting himself against the erosions of age and a history of chronic injuries to his right arm. The day is fast approaching when, if Singleton's batting doesn't shape up, his job as designated hitter will have to go to others.

Unfortunately for objectivity, Singleton is probably an even better man than a ballplayer. In 1982, baseball presented him the Roberto Clemente Award, given to the player who best exemplifies the game both on and off the field.

The general reaction within the game was, "Well, of course."

These days, Singleton still exemplifies the game: he exemplifies how hard and unfair and tormenting it can be.

A few days ago, Singleton sat beside his locker in Memorial Stadium and gave a resigned shrug and a laugh. "It's getting kind of ridiculous," he says.

This is how ridiculous.

With a week left in spring training, Singleton finally thought he'd licked 18 months of problems. Through two offseasons of rehabilitation, he had finally gotten his misbehaving right elbow and wrist and hand to the point where, for the first time in years, his right side was stronger at any sort of test than his left side. In addition, he was in his best shape as an Oriole--a dozen pounds trimmer and considerably harder than in some of his peak years. He was a man making one last great career stand and he seemed to be winning.

Twice in Florida he powered balls out of the park right-handed, one of the blows a tape measure shot. One day, he smoked a 400-foot drive off the wall to the opposite field through a strong wind and, in the dugout, Eddie Murray crowed, "Singy's back." Singleton, on second base, heard him and agreed.

"I really felt like I had it going," says Singleton. "I had to show people I could still hit the ball up the gaps and out of the park. I think I did . . .

"The whole spring training seemed like a normal familiar progression again. I was tentative early, then, after about 10 days, I started getting pitches in spots where I was looking for them and I started hitting the ball very hard. I got that old urge with the men on base."

A week before the season started, Singleton's 55-year-old father-in-law died. Singleton spent six days in Montreal helping his wife through the ordeal.

Asked if that wasn't terribly inopportune--throwing his training schedule out of whack, Singleton is surprised. He doesn't think that way. He and his wife had known what was coming for a long time and Singleton had been hoping that, if the death had to come, it would be at a time when he could give his wife all the time and support that she'd need.

"I have never seen my wife cry like that. I remember not knowing what to say to her for the first time in our lives. How much can you comfort somebody? Our (two) sons are young and I had to explain to them for her, too."

Pressed about how it affected his baseball, Singleton says, "I guess it came at a critical time."

When he showed up in Baltimore on the eve of opening day, Singleton discovered that his timing had gone a bit sour. A couple of rainouts, a few off-days and a road trip to the frigid Midwest did him no good. He "dialed 8" (a long-distance home run) in Cleveland, but he was getting rustier, not sharper.

So, one raw evening after a rainout, he stayed in the Memorial Stadium tunnel and hit against a pitching machine until he'd worked out all his frustrations as well as his hitches. The next morning, his back hurt. He played a doubleheader anyway. The next day, he knew he'd pulled a back muscle and done a good job of it. He sat out four games.

That's when it got ridiculous. Trying to speed the healing, he kept a hot pack on his back so long that he burned himself, raising a rectangle of red welts. "How would I like myself? Medium rare?" he says, looking at the ugly marks. "I'll tell the guys (on the team) I'm just working on my tan."

Singleton then went into the shower and, perhaps a bit disgruntled, ripped some tape off his big toes. A couple of minutes later, the Orioles asked him, "Why are you standing in that pool of blood."

"I didn't even know I was bleeding and it was gushing all over the floor," he says. "I tore the skin right off the toe.

"The way things are going, maybe I better call a cab to drive me home."

Perhaps that was Singleton's goofy and sad low point.

Two days later, in his first game back, Singleton tripled off the top of Baltimore's high left field wall in the 13th inning, missing an into-the-wind game-winning homer by a couple of feet.

As the Orioles left for their 10-day West Coast road trip, his spirits were on the rise.

"It's coming back. When the weather gets warm, it'll be okay. It's a little out of control right now. The bat's not going where it should . . . but I'm a perennially slow starter in the cold. Then, I always go to California and start hitting," says Singleton, who is batting an indeterminant .231 with four extra-base hits, but eight strikeouts, in 39 at bats.

"I don't like making outs," he says, his pride flaring. "I know I'm still capable. I haven't lost my confidence. In fact, last year made me more optimistic because I found out my problem was physical. It was my hand (atrophied muscles) and not age. At the end of '81, I didn't know what was wrong. It's like I'd turn the switch and the power didn't come on.

"Maybe I've put more pressure on myself . . . but I thought I did a pretty good job last year, considering (his injury). I hit .342 (in '82) with men in scoring position which was the highest on the club. I drove in runs when I had the chance."

Ken Singleton sees all the signs, hears all the whispers. No one needs to remind him that he hit .177 right-handed last season and that he hasn't hit a homer from that side since August '81. He's batting sixth now, not third. He's in his second year as a DH--a role that he's not sure suits him after 15 pro years as an outfielder; habits die hard.

Nobody has to remind Singleton that these are all clear signs of a veteran player who is being moved from the center of a team's plans to its fringes so that, if worse comes to worse, and he must be benched, the shock to the club will be minimized.

"I feel people pulling for me," he says.

Should his fans worry about him, start rubbing the lucky rabbit's feet for one of the nicest people in baseball to pull it all back together on the far side of 35 for a couple of more distinguished years--the way Carl Yastrzemski and Tony Perez and Willie Stargell and others have done?

No, Singleton insists, it's not time for good luck charms and novenas and the sentiment that hangs around beloved players when they're over the hill.

Where others see hard times coming, Singleton still sees glory. This student of the game and of himself knows the end will come, but he's almost sure it hasn't arrived. Not yet.

When he has doubts, Singleton only has to flex his right arm to be cheerful once more. "I can feel the difference. And it's a big difference. I just want to get hot one time," he says, laughing and looking at his new arm, "and see what it can do.

"The things that have happened delay it. But they don't undo it."