Sadaharu Oh has, in his own words, "spiritually and physically, hit a wall." So saying, baseball's all-time home run hitter today decared an end to his marathon playing career.

Oh cleared various Japanese big-league walls to the tune of 868 home runs in a 21-year career, compared to the U.S. record of 755 by Henry Aaron. This year, at age 40, he hardly let up, smashing 30 four-basers in the 19th successive year he has reached at least that figure.

The trim star of the Yomiuri Giants, with his distinctive lift of the right foot as he strode into his left-handed swing, reminded many of Mel Ott, the old New York Giant star. Korakuen Stadium in Tokyo, Oh's home park, reminded many of the Polo Grounds, a boon to Ott's home run production: Korakuen's faces slant in sharply to 295 feet down the foul lines.

Still, it was no mean feat to bat 302 lifetime, with such power, and Oh can be forgiven for not quite living up to his 40th birthday promise in May that "I am still completely confident. . . . I am determined to hit No. 900 before I bow out."

It is only semi-sayonara to Sadaharu. For the Yomiuri club, whose manager Shigeo Nagashima resigned last week after a third-place finish in the Central League, Oh now will shift to the coaching staff.

In Cleveland, tentative new Indians owners James Nederlander and Neil Papiano pledge a fresh start, traveling up whatever avenue proves needed to create a winner. "Cleveland has always been a great theater town," says Nederlander, who came up with a winner as coproducer of the hit musical "Annie." And while Gabe Paul is counted to stay on in the front office, he has offered a top management job to Tal Smith, victim of last week's celebrated bounce out of the Houston Astro general managership . . .

In Houston, those limited partners seeking removal of Smith's nemesis, General Partner John McMullen, say they are still working with enthusiasm toward that end . . . In Chicago, the White Sox board of directors reaffirms its support of would-be buyer Edward DeBartolo Sr. despite failure to win American League approval; DeBartolo hopes to persuade the AL owners to change their minds at the winter meetings beginning in Dallas Dec. 8 . . .

The San Diego Padres have retained Chuck Estrada, pitching coach under the past two managers, in that capacity under new skipper Frank Howard; so much for Dick Bosman's possibly joining Howard and Ed Brinkman. Good news for Estrada, maybe: relief ace Rollie Fingers says maybe he doesn't want traded after all . . .