While he did have some excellent college film, McDuffie was an outlier. With 29.75-inch arms — that’s only in the fifth percentile among cornerbacks — his lack of length was concerning. Since 2010, just one other cornerback with arms under 30 inches — Alabama’s Kareem Jackson — was selected in the first round. He’s been a safety his entire career.
But Kansas City made the right call. During the first seven games of his rookie season — when McDuffie was out with a hamstring injury — the secondary ranked 22nd in expected points added (EPA) and 24th in success rate. But after McDuffie returned in Week 8, it ranked 10th in EPA and fourth in success rate. This season, it ranks third in EPA and second in success rate.
When McDuffie has been on the field, the Chiefs have had one of the league’s best pass defenses. What does he do that makes him so valuable? In my opinion, it is because he’s a perfect slot defender.
Let’s look at the film.
To play the slot, you have to be able to blitz. The Baltimore Ravens are making a living having safety/slot Kyle Hamilton blitz on different simulated pressures. Defensive backs have to be comfortable getting downhill, defeating blocks and getting to quarterbacks fast.
McDuffie is already one of the NFL’s best blitzers.
McDuffie has to be one of the better blitzers in the NFL. Chiefs get into a 5-0 with another S off the edge, OL goes 5-down with RB getting Reid, but watch McDuffie not give the blitz to Kirk, so Kirk has zero idea he's hot off that side, and the closing speed/hitting power pic.twitter.com/zKoVY2yCPl— Nate Christensen (@natech32) November 14, 2023
On this play, the Chiefs are showing a 5-0 front — that is, four down linemen with a linebacker who has walked into the A-Gap — but also present safety Justin Reid as a blitzer. The Minnesota Vikings check into a 5-0 protection; each blocker is supposed to block the guy closest to them. If the safety blitzes, the running back will block him. Otherwise, he’s watching for a back side slot defender — in this case, that’s McDuffie.
McDuffie disguises his blitz wonderfully. He stays at depth to make the offense believe he is going to drop into coverage; the quarterback doesn’t have the protection account for him. So when Reid blitzes, McDuffie gets a free run off the B-gap — and the quarterback has no idea he’s hot from that side.
McDuffie’s timing and speed are incredible. His ability to disguise what he’s going to do — and have the athleticism to close quickly — makes it easier for defensive coordinator Steve Spagnuolo to blitz. Fellow cornerback L’Jarius Sneed is also a good blitzer, but McDuffie has taken Kansas City’s pressure packages to another level.
Fitting the run
The main issue teams have with their slot defenders is stopping the run. Since teams can’t afford to play base personnel against spread formations, defenses respond with nickel or dime personnel packages. That makes it harder to defend against the run. Teams then have to decide whether to move a safety down into the box or sacrifice the run defense by keeping a light box at the line.
Luckily, the Chiefs don’t have this issue — because they have McDuffie.
This is a 5'10, sub-200 lb CB who the Chiefs put in the condensed slot, trusting him to set the edge against the run. The outside swipe keeps him clean and he hooks around to help stop run pic.twitter.com/XwUcDg3XPz— Nate Christensen (@natech32) November 13, 2023
I think it's very cool that we have a CB who also is very capable of stepping into the box and fitting the run if needed. The Chiefs are in a 5-1 here with 3 LB, McDuffie is unblocked, but it's still just very cool. NOt sure how many guys besides like Ramsey/Taron Johnson do this pic.twitter.com/woosQ2ONRT— Nate Christensen (@natech32) November 14, 2023
When teams go into lighter personnel, Kansas City can stay in two-high coverages — because even at his shorter stature, McDuffie is an incredible run defender. His toughness, speed, and tackling ability are all outstanding. The Chiefs are perfectly willing to have McDuffie insert into running plays, beat blocks and tackle in space.
This is another way that McDuffie makes Spagnuolo’s job easier. He can protect his outside cornerbacks with two safeties and still trust that his run defense will be effective. During his tenure, Spagnuolo has always coached his cornerbacks to tackle — and McDuffie is one of his star pupils.
Dealing with RPOs
Defenses often struggle with run-pass options — mainly because it’s hard to find a slot cornerback who can defend against both options. If you’re helping defend a run, you’d better be able to tackle and deal with blocks in space.
Luckily, McDuffie can do this very well.
Trent McDuffie is an unbelievably good player defending screens. Whether it's him running a screen inside-out, tackling off the edge, or just destroying the point-man blocker, he does incredible stuff against RPOs and bubbles pic.twitter.com/cqchGCLIXv— Nate Christensen (@natech32) November 14, 2023
McDuffie's physicality tackling has always been a standout trait, including his ability to knock the ball out. You would never guess he's one of the smaller players in the league pic.twitter.com/QYXRZcxjs1— Nate Christensen (@natech32) November 13, 2023
Whether it’s by playing a screen inside-out, taking on the main block or tackling off the boundary, McDuffie makes screen plays a lot less palatable for offenses — and without screens, a lot of an offense’s RPO playbook vaporizes. Without these plays, it’s harder for offenses to function on early downs — and the defense can play faster.
Playing man coverage
McDuffie is also effective in playing man coverage from the slot. While he’s an incredible athlete with elite agility and physicality, he’s also an astute football player.
KC in C1 here, drop safety down to help dropping LB (Chenal). McDuffie's only help is Tranquill in the high hole on the other side but still uses his outside leverage to help funnel Amon-Ra there. Slows the top of his break with outside arm locked, runs across into help pic.twitter.com/R1tk58wazB— Nate Christensen (@natech32) November 13, 2023
On this play against the Detroit Lions, Kansas City is playing Cover 1; the safety is going to drop down to cover the running back in the flat. The only middle-of-the-field defender is dropping linebacker Drue Tranquill, who is playing the weak side hook.
McDuffie knows he has to funnel wide receiver Amon-Ra St. Brown — one of the league’s premier middle-of-the-field wideouts — to Tranquill. So he has to slow down St. Brown’s stem at the top of the route, throwing off the route’s timing.
This play highlights not only McDuffie’s excellent physicality, but also his football IQ.
The bottom line
It’s almost as if McDuffie was built in a laboratory to play in a modern NFL defense. He can play as a cornerback on the outside or in the slot — and also as a safety. He’s an incredible man coverage defender and an intelligent zone defender. He’s one of the league’s best blitzers — and to top it all off, he’s a willing (and outstanding) run defender.
There are maybe two or three other NFL players who can do all of that — and McDuffie has proven his ability in all of these areas after barely a full season of play.
The Chiefs’ defense has been outstanding this season — but is that performance sustainable? I believe that it is. In the team’s upcoming opponents, I don’t see a team where the defense doesn’t have the personnel to matchup against the offense — and all of that revolves around McDuffie. The team’s ability to weaponize him — and scheme him against any matchup — allows it to avoid sacrificing defensive structure in order to defend against the run or pass.
I thought Marcus Peters was going to be the best Kansas City cornerback I would ever see. I was wrong. It’s Trent McDuffie — and frankly, it’s not even close.