Patriots' second-half surety is gone

Remember that feeling of inevitable victory?

During past decade's dynastic stretch, New England Patriots games became predictable. Maybe it caused some complacency among their fans.

Up in the third quarter? An extended kitchen trip seemed forgivable. Ahead going into the fourth? Just sit back and ride the wave to victory.

The outcomes seemed so predetermined, fans almost felt guilty. Almost.

Back then, the Patriots were like vintage Jonathan Papelbon. Give them a late lead and you could forget about it. Since then? Well, have you tuned in to a Red Sox game lately?

From 2002-08, there were 371 NFL games in which a team led at halftime but went on to lose. The Patriots suffered just one of those losses -- a 2004 second-half comeback by the Miami Dolphins.

New England did this despite leading at halftime more than any other team. In all, they were 66-1 with a lead at intermission. If anything was a sure thing, you could bet on the Patriots holding a late lead.

On Sunday, the Patriots led 14-10 at halftime, but the Jets scored 18 unanswered points to win the game, 28-14. It was just the latest indication the honeymoon is over.

Since 2009, the results have not been nearly as favorable. The Patriots have led at the half 14 times, tied with the Packers for most in the NFL, but they are just 9-5 with a halftime lead, the 24th-best winning percentage in the NFL. Only the lowly Rams match that loss total.

Now, perhaps margin has something to do with it. Were those dominant Patriots squads putting up such large halftime margins that losing wasn't much of an option?

Not exactly.

Granted, the Patriots are 6-0 with a halftime lead of more than 10 since the start of last season. From 2002 to 2008, they were 27-0 in such contests.

But back then, even with a halftime lead of 10 points or fewer, the Patriots were 39-1, best in the NFL. Over the past two seasons, they are 3-5, the 28th-best winning percentage in the league.

So what's the cause of all of this? How did the Patriots become Heathcliff Slocumb when they used to be Mariano Rivera?

Perhaps it all started with a game that all those numbers ignore. You see, those Patriots had one regular-season loss when leading at the half. Include the playoffs, and there were two more. Those other two just might be the most gut-wrenching losses in franchise history.

The first was the 2006 AFC Championship Game where the Patriots blew a 15-point halftime lead to the Colts. The other? A game that requires no introduction.

Leading up to Super Bowl XLII, Tom Brady was 76-3 with a halftime lead. The Patriots led the Giants 7-3 at halftime. That same score held after the third quarter. Brady was 80-2 with a lead going into the fourth quarter.

What happened next requires no reminder, but consider this: Including that Super Bowl loss -- and by virtue of missing the 2008 season -- Brady has lost six of the past 15 games in which he had a halftime lead.

A stunning 76-3 before that heartbreaking Super Bowl loss. A pedestrian 9-6 since.

The 2009 Patriots certainly had a multitude of weaknesses -- namely a dormant pass rush and ineffective secondary that allowed opponents to have a 124.7 passer rating when holding a lead.

Sunday made it clear that 2009 was not an aberration. It also underscored the fact that the defense -- while not helping -- is not the main problem.

New England didn't score in the second half on Sunday. In fact, in three of their past five losses after leading at halftime, the Patriots failed to score a single second-half point. No defense can be expected to hold a lead with no support.

Much the way he deservedly received credit for the team's success, ultimately the blame falls on Brady.

One only needs to look back on Sunday for the latest example. Trailing 21-14, Brady threw an interception on the first play of the fourth quarter. Now, the interception was hardly Brady's fault. However, Brady had two fourth-quarter possessions while the game was still within seven. He went 0-3 with an interception.

It's a jarring continuation of a trend that plagued him in 2009. Last year, he had a 52.4 passer rating in the fourth quarter with the game within seven points, which ranked 30th in the NFL, according to STATS LLC. It included just one touchdown compared to three interceptions, and no completion longer than 18 yards.

Add in Sunday's game, and Brady now has a 44.5 passer rating in those close fourth-quarter situations since 2009. That's 34th in the NFL, better only than Matthew Stafford and Jake Delhomme. Not exactly the company he'd like to keep these days. Back in the glory years, Brady had an 87.2 passer rating in those situations.

And, of course, any discussion of Brady requires mention of Peyton Manning. He has an NFL-best 132.5 rating in those situations since 2009.

Certainly, not all of the offensive woes rest on Brady's shoulders. When holding a second-half lead from 2002 to 2008, the Patriots averaged 3.74 yards per carry and ran the ball 58 percent of the time. Since 2009, that has dropped to just 3.38 YPC. Without a reliable late-game rushing attack, just more than 50 percent of plays are on the ground.

Likewise, it's still the Patriots defense that's giving up those halftime leads.

But Brady just isn't bringing them back. While Manning had seven fourth-quarter comebacks last season, Brady had only one. When his team was trailing in fourth quarter, Manning had a 140.1 passer rating. Brady? A 60.0 passer rating, just 34th best in the NFL.

Is the magic gone?

Heading into this Sunday's game against the Buffalo Bills, the Patriots can take solace in this: Including the postseason, they've won 53 straight games in Foxborough when leading at the half.

With a lead, at least home still feels like a familiar place.

Jeremy Lundblad is a researcher with ESPN Stats & Information. He provides statistical analysis for ESPNBoston.com.