Why, oh, why the wide nine?

After five games, it's become remarkably clear: The Eagles have neither the personnel nor the defensive coordinator to make the wide nine scheme work effectively for four quarters.

Sure, there have been glimpses of the kind of pressure the wide nine can generate for this defense. But each week the run totals top 100 yards as running backs zip through huge gaps as wide as Andy Reid's waist. Each week opposing offenses script and execute plays designed to exploit the wide nine. And each week the sack numbers decrease.

The argument for keeping the scheme is as weak as Jarrad Page's tackling.

And yet, Reid said Monday following the Eagles' fourth straight loss - a 31-24 defeat at the hands of the Buffalo Bills - he's sticking with the wide nine. So be it.

"You obviously saw it work in the second half very effectively," Reid said. "We've just got to continue to work with it. Listen, anything new you've got to work with and work out the wrinkles and get it right.

"Players, they have to learn it, coaches have to learn it, particularly the new coaches. So it's a joint effort there."

This wasn't a smokescreen. Reid believes in the system. He has to. A series of coaching moves made in the offseason were based strictly on Reid's desire to bring the wide nine to Philadelphia. If his pass-happy offense has had problems blocking against it then so, too, will the offenses that face his defense.

So Reid got one of the great instructors of the wide nine - defensive line coach Jim Washburn. Luring Washburn away from Tennessee was the first coaching hire Reid made after he fired Sean McDermott as his defensive coordinator.

It was a peculiar move. A new coordinator would surely want to bring in his own people and implement his own scheme even if Washburn is considered one of the best in the business.

What probably happened as the Eagles defensive coordinator search turned farcical was that interviewed candidates balked at the idea of coming aboard with the stipulation that the wide nine would be used here - take it or leave it. There aren't many coaches that use it, although it has been around in one form or other for many years.

So that left Juan Castillo. And, well, Castillo would do whatever Reid and Washburn wanted. He was an offensive line coach wishing to become a defensive coordinator. Castillo would have agreed to the wide nineteen.

The wide nine, in theory, can work quite splendidly. But you need two components: Defensive ends who torpedo past tackles, and linebackers and safeties who can fend off blockers, fill run-gap responsibilities and make tackles.

The Eagles already had a Pro Bowl-caliber end in Trent Cole and two complementary pieces in Juqua Parker and Darryl Tapp. Jason Babin, who thrived under Washburn as a Titan last season, was signed as a free agent, giving Castillo a solid first component.

At linebacker and safety, however, Stewart Bradley and Quintin Mikell were not re-signed as free agents, and were instead replaced by rookie Casey Matthews and a former seventh-round draft pick in Kurt Coleman.

Both players eventually were benched. Their replacements - Jamar Chaney and Nate Allen - have been marginally better. Page took Allen's job at the other safety spot before the season but has been an unmitigated disaster. Coleman could have his starting spot back by in Sunday's game at Washington.

Needless to say, Reid did not provide Castillo with the necessary parts to make the wide nine into a 10. What the Eagles should have done was sign former Tennessee middle linebacker Stephen Tulloch. The Titans, as a whole, might have been dreadful last season, but they could stop the run, holding ballcarriers to 3.9 yards a tote.

The 30th-ranked Eagles run defense is allowing 5 yards a carry.

Tulloch, instead, went to Detroit. Why? Because former Titans defensive coordinator and current Lions head coach Jim Schwartz also employs the wide nine. Go figure. Detroit is 4-0 and its defense 11th overall heading into Monday night's game against the Bears.

The Eagles, meanwhile, are left with a defense that teams continue to abuse on the ground and with a variety of short pass plays that take advantage of the defensive ends who jet straight for the quarterback.

Reid was right, the defense performed better in the second half, but it wasn't because of the wide nine. It was because the leading Bills took their foot off the gas and because Castillo dialed up a number of heavy blitz packages that actually worked.

It's time to scrap the wide nine, tighten up the line and get back to the type of aggressive scheme Jim Johnson used when he ran the defense.

And this point, why not?

Contact staff writer Jeff McLane at 215-854-4745, jmclane@phillynews.com or @Jeff_McLane on Twitter.