Pretend for a moment that there's a continuum in football. At one end, there's the physical: the stuff you can observe and, to some degree, quantify. Technical ability. Stamina. Athleticism. Strength. We can roll many of these things up in cold, hard numbers. Analytics can't measure them directly, but they can give us a good sense of their outcomes. Strikers who score goals are good. Defenders who don't concede are good. Teams with good xG differences are good.

At the other end is the metaphysical. The fuzzy stuff. Heart. Personality. Decision-making (and its cousin, experience). Mentality. This too tends to show up in numbers, albeit mostly when the numbers somehow surprise us. You tend to notice when the qualities aren't there, rather than when they're present. And because it's intangible, know-it-when-I-see-it stuff, it's sort of a one-size-fits-all. It also makes some people (like me) somewhat uncomfortable precisely because it's intangible. And, partly, because I've had enough of folks who see a team get thoroughly outplayed but nick a winner with a lucky smash-and-grab and then be told they "wanted it more," "played with more passion" and "had a winning mentality."

All of which brings us to Chelsea after their 2-2 home-draw-that-feels-like-a-crushing-defeat with Arsenal. (And yes: when you're a goal and a man up at home for more than an hour, playing against a side 10 points back in the table and missing their best striker, that's what it feels like.) It's worthy of review ahead of Saturday's FA Cup fourth round trip to Hull City (stream live on ESPN+, Saturday, 12.30 p.m. ET)

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Chelsea recorded 19 shots on goal to Arsenal's two. They notched 2.09 xG to Arsenal's 0.5 effort. They hit the woodwork but then, they fizzled out. Five times this season -- against Arsenal, Bournemouth and Sheffield United at home, Brighton and Newcastle away -- Chelsea have conceded late goals that cost them points. Some were unavoidable (witness Alireza Jahanbakhsh's remarkable overhead kick) and some were the result of individual or collective blunders, but the upshot is that without those late goals, they'd be second, two points ahead of Manchester City. Their average xG in each of those games was more than a goal higher than their opponents, which raises the question of just why they ended up scratching on the eight ball.

This is where you either chalk it up to the wonderful randomness of football or you get a bit metaphysical. Chelsea lend themselves to this reading because they are packed with young players, many of them Academy graduates. Their 15 most frequently used players by minutes played features seven guys who are 23 or younger. That probably doesn't impact the mental toughness/personality side as much as grizzled ex-pros will tell you -- put differently, you don't suddenly grow some when you hit your late 20s -- but it does impact decison-making and experience.

Simply put, most of them have very few games under their belt against Premier League standard opposition. They've played plenty of games, but not against guys this skillful, smart and experienced. Reading what is about to happen takes that little bit longer -- neurons fire that little bit more slowly without an ingrained data set of past experiences -- and so decisions are that little bit poorer.

Over the entire course of a game, and all things being equal, it matters less. In the dying minutes, when pressure mounts, legs get heavy and minds get blurry it can make all the difference. Youth also impacts fatigue.

One former Chelsea official I spoke to, who has a wealth of experience dealing with younger players, made the simple point about fatigue. The likes of Fikayo Tomori, Mason Mount, Reece James and Tammy Abraham all played plenty last year in the Football League, but what they didn't do very often is get on a plane, unlike this year with European and international commitments. It's not that first-class travel and overnight stays is physically punishing; rather, it's that it messes with your training rhythms and at that age, if you're unaccustomed to it, it can make a difference.

There is probably something to be said about an even fuzzier concept: leadership. It's tempting to wistfully reminisce about the Chelseas of yesteryear with their Terrys and Lampards, Cechs and Drogbas and talk about how this is simply a different group. Look around this group and the closest you get in terms of leadership types is Antonio Rudiger and Cesar Azpilicueta. Most of the others are more low-key or simply lead-by-example rather than chest-beating types.

Again, this is the sort of quality that becomes "a thing" only when a team stumbles but late Tuesday night at a frosty Stamford Bridge, that's what you saw. Rudiger shouting, Azpilicueta haranguing, yes, but also Abraham limping, Barkley meandering, Emerson fretting, Jorginho spinning and Mount searching. They didn't look a side with the "been there, done that" confidence to see out games they had already won. They looked soft, especially to those who remember the veteran-filled title-winning sides of yesteryear with the guys like Diego Costa, Nemanja Matic, Branislav Ivanovic, Gary Cahill and, yup, John Terry.

The good news is there's a flip-side. First and foremost, if you'd told Frank Lampard that his Chelsea team would be in the knockout stages of the Champions League and fourth in the table at this stage of the season, after the summer transfer ban, he would have taken it. Beyond that, they have plenty of the physical traits mentioned above and those are the building blocks of any top side in modern football.

As for the metaphysical ones, some will be developed, some will be unearthed and yes, some players won't make the grade at Stamford Bridge. Because tempting as it is to throw in the home-grown youngsters and believe that all they need is trust and playing time, football doesn't work that way. But several will and those who won't will help fill the coffers, as has been Chelsea's business model over the past decade.

Lampard's Chelsea are ahead of the curve in what is a transition season. Many of the points dropped are simply the growing pains of a young inexperienced side that may be short on experience leader-types. The challenge will come later: deciding which guys to keep and stake the club's future on and which to shed.