The New England Patriots win because of completeness. They have the biggest star in football in Tom Brady, but their five-Lombardi dynasty has been built on being deeper, more versatile and more prepared than everybody else. They thrive less on strengths than on a dearth of weaknesses. The things they aren’t great at, they’re good enough at.Their performance Thursday night ran antithetical to the Patriots’ typical totality. The Patriots never have obvious holes, but their startling, 42-27 loss to the Kansas City Chiefs revealed a glaring void they must fill to get back on course as surefire Super Bowl favorites. The Patriots entered their opener as a colossus, with not a care in the world. They should exit it with their deepest concerns reserved for their nonexistent pass rush.The Patriots allowed Alex Smith, a quarterback known/maligned for checking down and dumping off, to pass for 368 yards and four touchdowns on 28-of-35 passing. The totals included passes of 78, 75 and 25 yards. The Patriots sacked Smith three times. On one, he tripped and fell. The two others, both by Trey Flowers, accounted for losses of three yards and one yard.New England only hit Smith four times at all, including the sack when he slipped. On many of his downfield attempts, Smith had ample time to scan the Patriots’ secondary without a soul near him. The Patriots did not harass Smith, did not shrink his pocket or force him to make plays on the move.The Patriots never compile gaudy sack totals. Last season, they led the league in three-man rushes. Coach Bill Belichick’s defenses lean toward bend-don’t-break. He rarely gambles with heavy, exotic blitzes, and New England pass rushers do not veer from their lanes. But the Patriots do manage to consistently pressure quarterbacks, to force them into uncomfortable throws. They allowed Smith a shockingly comfortable night.It has become silly to criticize the Patriots for dealing away linebackers Chandler Jones and Jamie Collins before and during last season, given that they won the Super Bowl without them and would have had difficulty finding salary cap room to pay them. But losing Jones and Collins, both hyper-athletic defenders who weren’t perfect fits for Belichick’s defense, reduced the Patriots’ pass-rush options, and they have not come close to replacing their skills.Belichick can seemingly scheme his way out of any problem, but this one is a matter of personnel. Linebacker Rob Ninkovich retired at the outset of training camp. The Patriots used their top pick in the draft on defensive end Derek Rivers, but lost him in training camp to a season-ending knee injury. They traded acquired end Kony Ealy from the Panthers in the offseason, only to cut him at the end of camp.The Patriots conceded they had a dearth of pass rushers five days before kickoff, when they dealt a late-round pick to the Seattle Seahawks for outside linebacker Cassius Marsh. Their transactions make clear they know it’s a problem.It worsened in the third quarter, when Dont’a Hightower, perhaps their best pass rusher, suffered a knee injury and spent the rest of the game on the bench. Hightower’s status for the Patriots’ Week 2 game against the New Orleans Saints remains in question. Before Hightower’s injury, which came with about five minutes left in the third quarter, the Patriots allowed 6.6 yards per play. After Hightower exited, the Patriots surrendered 242 yards on 20 plays, or 12.1 per snap.The Patriots’ stunning loss will lead to many explanations of what went wrong or what needs fixing. It was their hubris. It was a lack of Julian Edelman. It’s age finally catching up to Brady. There are varying degrees of merit to all of them. But the first thing the Patriots need to do is find some defensive players who can rush the passer.The Patriots rarely have any holes at all. Right now, they have a giant one that just got exposed in embarrassing fashion. On a night they planned on celebrating, the Patriots were exploited. Belichick can fix it, but it may take reinforcements.