Should any team win both havlves of baseball's split season, it will be rewarded with a possible four games at home in the best-of-five mini-playoffs, it was announced yesterday in New York by Commissioner Bowie Kuhn and the two league presidents.

All the division series will begin Oct. 6.

Should different teams win the two halves, the first two games will be played in the home stadium of the second-half winner, with the first-half champion being at home for the remaining games.

If the same team wins both halves, it will be paired in the division series with the team in its division that compiled the second-best record for the year. The opening game of the series will be on the field of the second-best team, with the two-time champion being home for the remaining necessary games.

The league championship series will begin Oct. 13 and the World Series on Oct. 20.

The world champion Philadelphia Phillies, the Los Angeles Dodgers, the New York Yankees and the Oakland A's were the first-half winners. The second-half of modern major league baseball's first split season began yesterday. A strike shut down the regular season June 11 for 59 days.

Meanwhile, the New York Daily News reported that a group of major league players, including Dave Winfield, Pete Rose and Johnny Bench, have been cited in grievances filed by club owners, seeking to recover salaries paid during the players' strike.

The newspaper said the grievances were filed in response to default notices filed by the players. Joel Youngblood and Dave Kingman of the New York Mets and Winfield, Tommy John and Dave LaRoche of the Yankees were named in addition to Rose, of the Philadelphia Phillies, and Bench, of the Cincinnati Reds.

Bench and Youngblood claimed they were on the disabled list during the 50-day strike and were entitled to compensation. Kingman claimed in his default notice that his contract called for deferred compensation. Rose, John and LaRoche argued that their contracts provided for salary payment, strike or no strike.

Winfield had claimed previously that his withholding taxes for his paycheck dated June 15 were too high.

A Denver newspaper said that Kuhn said he expects the National League to soon begin considering expansion and that Denver would be an ideal location. Washington, where a new team is considered a dead issue, cropped up in this picture from an unidentified source.

Kuhn told the Rocky Mountain News that talk of expansion had been held up due to the baseball strike, but now that the labor dispute has been resolved negotiations were expected to get under way.

The News quoted one league executive, who asked to remain unidentified, as saying he was optimistic about expansion.

"The owners have lost a lot of money -- millions -- during the strike, and they won't be able to recoup most of that," the executive said. "But the National League can get back some of that by expanding to two more cities like Denver and Washington or Miami or New Orleans or wherever.

"Charge them $16-20 million for the franchises. I think it will happen for the 1983 season."