Joe Gibbs had seen it before, although he didn’t remember: On Dec. 7, 1986, his Washington Redskins turned the ball over seven times and lost to the New York Giants.

They equaled that figure at the Meadowlands on Sunday, where the Giants got seven more and beat Gibbs and Washington 20-14.

“I think back and I don’t know that I have seen that many mistakes,” Gibbs said. “Give them all the credit, but we just can’t do what we did either.”

Sunday was a perfect example of why turnover differential is the most important statistic in the game.

In 12 of the 15 games, the winners had more takeaways than the teams they beat and in seven of those games, turnovers were clearly the deciding factor:

• The Giants got 17 of their 20 points directly off turnovers, including a 16-yard touchdown on a fumble return by linebacker Barrett Green. Three of their four interceptions came deep in their own territory, preventing Washington scores.

• Chicago’s upset win in Green Bay was the result of a 14-point swing just inside the 2-minute warning in the first half. On first down from the 2, Brian Urlacher stripped Ahman Green of the ball and Mike Brown scooped it up and ran 95 yards for a touchdown, making it 14-3 Chicago instead of 10-7 Green Bay.

• Jacksonville, which is 2-0 despite just 20 points in two wins, was the beneficiary of a fumble by Denver’s Quentin Griffin at their 23-yard-line with 37 seconds left in their 7-6 win. Had Griffin held on to the ball, the Broncos were within easy range of a game-winning field goal by the reliable Jason Elam.

• Indianapolis and Tennessee were tied 17-17 when Steve McNair threw what looked like a go-ahead touchdown pass to Derrick Mason early in the fourth quarter. But the Colts’ Nick Harper pulled it away from Mason in the end zone and Indy then went 80 yards for the go-ahead score in a 31-17 win.

• In Cincinnati, the Bengals’ only touchdown in their 16-13 win over the Dolphins came on Brian Simmons’ 50-yard interception return.

• The difference in Oakland’s 13-10 win over Buffalo was Ray Buchanan’s interception and 27-yard return that set up a field goal.

• Seattle’s 10-6 win in Tampa stemmed directly from two interceptions, the first by Marcus Trufant to set up the game’s only touchdown, the second by Michael Boulware to stop the Bucs’ final drive. The first came off Brad Johnson, the second off Chris Simms, making his first regular-season appearance after replacing an ineffective Johnson.

The Giants’ seven takeaways were almost a third of the 22 they had all of last season, when they tied for last in the NFL with Buffalo with a minus-16 turnover differential. After two games this season, they are tied for first with Detroit and the Jets at plus-5.

One of the defensive standouts was tackle Fred Robbins, who had two sacks, forced a fumble that set up a touchdown and tipped a ball and intercepted it himself. Robbins had just a half-sack as a part-time starter for Minnesota the past two seasons. He was signed for a fraction of what the free-spending Redskins paid Cornelius Griffin, the player he is replacing.

“Turnovers are part of the formula,” said Giants coach Tom Coughlin, roasted on the network pregame shows Sunday for fining players for not being “early enough” to meetings. “You love to be in the position where the other guy is turning it over and you’re not.”

The game-turning play in Green Bay also came from a team with a new coach, Lovie Smith, the former defensive coordinator of the Rams. The last two times he faced the Packers with St. Louis, Smith’s team forced 10 turnovers.

When he was hired by the Bears eight months ago, Smith identified Green Bay as the team he wanted to beat the most and implied that he knew how.

That impressed at least one Packer.

“I’ve never been in a fight where some guy told me he was going to beat me up and he beat me up,” Green Bay linebacker Nick Barnett said.

Turnovers will do that.