NEW YORK  — Baseball has labor peace while the NBA is stopped and the NFL nearly came to a standstill.

“We’ve learned,” baseball Commissioner Bud 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 to teams for losing free agents, expands salary arbitration by a few players and for the first time allows teams to trade some draft selections.

It also adds unprecedented restraints on signing bonuses for amateur players coming to the major leagues from high school, college and overseas, perhaps hurting MLB as it competes with the NFL and NBA for multisport talent.

“If I’ve got a great athlete, why am I going to go to baseball? I’m going to focus on the other sports,” said agent Scott Boras, who has negotiated baseball’s highest signing bonuses.

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.”

Other highlights included: requiring players to play in the All-Star game unless injured or excused; expanding instant replay to include decisions on foul lines and traps, subject to an agreement with umpires; banning smokeless tobacco products during televised interviews by players, managers and coaches; requiring players arrested for DWI to undergo mandatory evaluation; and wearing improved batting helmets manufactured by Rawlings by 2013.

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.

“It meant a great deal to me personally, and a great deal to our sport,” Selig said.

Random testing for HGH will take place during spring training and the offseason, but there is no agreement yet on random testing in-season. There can be testing at any time for cause.

Although the NFL has wanted to start HGH blood tests, its players’ union has thus far resisted.

“The agreement to begin testing puts baseball ahead of other American professional sports leagues and is a credit to their leadership,” Rep. Henry Waxman said. “It will be important that the testing be extended to the regular season to avoid creating a loophole in the new policy.”

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. In addition, the number of offseason urine tests will increase gradually from 125 currently to 250 before the 2015 season.

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.

“I think having a second wild-card team is great for the game,” said NL MVP Ryan Braun of the Milwaukee Brewers. “I think it adds intrigue, it adds excitement. If you look at what the wild card, the first wild card, has done for baseball over the last few years, it’s made games late in the season relevant for everybody.”

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.