NEW YORK - Baseball Commissioner Bud Selig and union head Michael Weiner smiled and exchanged handshakes while others in the room dug into knishes and pigs in a blanket.

Not exactly the kind of scene that played out in sports labor talks this year.

Baseball ensured itself of 21 consecutive years of peace at a time the NBA season might be canceled because of a lockout and the NFL still is recovering from its CBA negotiations.

"We've learned," Selig said Tuesday after players and owners signed an agreement for a five-year contract running until December 2016. "Nobody back in the '70s, '80s and the early '90s, 1994, would ever believe that we would have 21 years of labor peace."

The agreement makes MLB the first pro major league in North America to conduct blood tests for human growth hormone, allowing it during spring training and future offseasons but for now only studying whether it will be implemented during the regular season.

"MLB and the players union should be applauded for taking the strong step to implement the HGH test at the major league level to protect clean athletes," said Travis Tygart, chief executive officer of the U.S. Anti-Doping Agency. "This is great progress in MLB's effort to protect the integrity of baseball at every level."

The deal, which must be ratified by both sides and drafted into a formal contract, expands the playoffs from eight to 10 teams by 2013, lessens draft-pick compensation for free agents, expands salary arbitration by a few players and for the first time allows teams to trade some draft selections.

Following eight work stoppages from 1972-95, baseball reached its third consecutive agreement without an interruption of play. The agreement was signed three weeks before the current deal was to expire Dec. 11, the second straight time the sides reached a deal early.

Baseball seems to have learned the lessons of the 1994-95 strike, which wiped out the World Series for the first time in nine decades.

"I think our history is more important than what's happening in other sports," said Michael Weiner, who took over from Donald Fehr as union head last year. "It took a while for the owners to appreciate that the union is not only here to stay, but that the union and its members can contribute positively to a discussion about the game - about its economics, about the nature of the competition, about how it's marketed in every way."

An initial positive test for HGH would result in a 50-game suspension, the same as a first positive urine test for a performance-enhancing substance. HGH testing in the minor leagues started late in the 2010 season.

Former union head Marvin Miller, who spoke to Weiner on Tuesday, praised much of the agreement but was critical of the HGH testing.

"It's the same as steroids. There's not a single test worldwide (proving) that it improves athletic performance, not one," he said. "I don't know if it does, and neither does anyone else."

The sides will explore in-season testing, but the union wants to make sure it's done in a way that doesn't interfere with players' health and safety.

"The players want to get out and be leaders on this issue, and they want there to be a level playing field," Weiner said. "The realities, though, are that baseball players play virtually every single day from Feb. 20 through October. And that's unlike any other athlete - professional or amateur - who's subject to drug testing. We want to make sure that we're doing everything we can on the HGH issue, but that it be consistent with not interfering with competition and not interfering with players health and safety."

As for the playoffs, there will be an additional two teams that will give baseball 10 of 30 clubs in the postseason. In the NFL, 12 of 32 teams make the playoffs. In the NBA and NHL, 16 of 30 advance.

The wild-card teams in each league - the non-first place teams with the best records - will meet in a one-game playoff, with the winners advancing to the division series. Manfred said a decision on whether the expanded playoffs would start next year likely will be made by the January owners' meeting.

This agreement also calls for the Houston Astros to switch from the NL Central to the AL West in 2013, leaving each league with three five-team divisions and a new schedule format that's still being determined. It's baseball's first realignment since the Brewers went to the NL after the 1997 season.

Teams will be allowed to have 26 active players for day-night doubleheaders, provided they are scheduled with a day's notice in order to give clubs time to bring up someone from the minor leagues.