This weekend’s NFL playoff games will be the first in which the league’s new postseason rules for overtime are eligible for use, and those on either side of the debate over the altered format admit they might not know how well it works until it is implemented.

The new system, which owners approved by a 28-4 vote in March, eliminates the possibility of a team winning with a field goal on the opening possession of overtime.

The team that gets the ball first in overtime can win the game by scoring a touchdown. If that team gets a field goal, its opponent gets a possession with a chance to tie the score with a field goal or win it with a touchdown. If that team gets a tying field goal, the game proceeds on a sudden-death basis. If neither team scores on its first possession of overtime, the game is sudden death from there.

“I don’t know if I’d say I’m eager” to see the new format utilized, said Atlanta Falcons president Rich McKay, co-chairman of the NFL’s competition committee. “I guess I would say I am interested to see if there are any strategic changes that we didn’t anticipate. We’ll need a few years to get a large enough sample. I don’t think we’ll be able to say after just a game or two. Who knows, we might not even have one this year.”

One of the teams that voted against the proposal, the Baltimore Ravens, plays a first-round AFC playoff game Sunday at Kansas City.

“I am a proponent,” New York Giants co-owner John Mara said. “I probably would have been comfortable using it in the regular season as well. But this was the best possible solution. It was a compromise so the most possible people could be comfortable with it. I am anxious to see how it works.”

Owners approved the measure for postseason play only, at least for now. Regular-season overtime games continue to use the format in which a coin flip determines which team gets possession first and the first team to score any points wins.

Not everyone is a fan.

“I don’t know why in the world you’d change something for the playoffs,” former NFL coach Dan Reeves said. “You play 16 games under one rule, then change for the playoffs? I think the rule we have is probably a better rule. Even if you don’t get the ball first, you have a chance to play defense and get the ball back. I worry about injuries if you’re making the game longer. Fatigue is what creates injuries. It’s already been a long season.”

Competition committee members said the change was necessary because a growing percentage of overtime games were being won by the team that won the coin flip, in part because of improved field-goal accuracy. Even so, players expressed opposition to the proposal during a meeting among competition committee members and representatives of the players at last year’s NFL scouting combine. Some coaches also were critical after the owners’ vote in March was taken without the coaches present.

A coach potentially now faces a decision about whether to keep his offense on the field for a fourth-down gamble or kick a field goal on the opening possession of overtime, knowing the other team gets a possession after a field goal. There also has been some talk that a coach might opt, especially in certain weather conditions, to put his team on defense first upon winning the overtime coin toss, knowing he could allow a field goal and still be assured of a possession to try to tie or win.

The NFL has had 27 overtime postseason games since 1958, including two in last season’s playoffs. The Arizona Cardinals beat the Green Bay Packers last January with a defensive touchdown after losing the overtime coin flip. The New Orleans Saints beat the Minnesota Vikings in last season’s NFC title game with a field goal on the opening possession of overtime after winning the coin toss. Yet the Vikings voted against the overtime proposal in March along with the Ravens, the Buffalo Bills and the Cincinnati Bengals.