After an afternoon in the sweet spot, when everything shone around him, Martin Odegaard did what he always does.Irrespective of whether a game goes well or badly, whether he feels elated or the weight of Arsenal’s world bears down on his shoulders, he makes a point of walking around the entire pitch to applaud the supporters.Having orchestrated an eye-catching 2-1 home win against Chelsea, Declan Rice came up behind Odegaard and shoved him closer to the North Bank. Rice is an accomplished hype man, and he wanted to make sure everyone made a fuss of Odegaard after a display of such refined excellence; even his heatmap probably looked like a work of art.A reborn Odegaard is central to the way Arsenal have started their title defence.The way he buzzed through this absorbing game, creating time and space with nimble trickery, pressing one moment and dropping to receive the ball the next, helped to create a template for the way Arsenal set about playing precise patterns at high speed.All game, he wanted to try things, to instigate things, to exert control and forward momentum. He brought dynamo energy fused with silky technique. “He is playing with real joy,” Arsenal manager Mikel Arteta said afterwards. But just as significantly, Arteta also noted that his captain felt he had a point to prove after missing a lot of football, and struggling for rhythm, while his body let him down and his resilience was tested over the past couple of seasons.The equation behind Odegaard’s renaissance is the sum of various factors: a happy footballer plus flourishing confidence plus reliable fitness equals the freedom to play at an optimal level.Looking across the team, he is not the only one in this zone.Kai Havertz excelled on Sunday too and demonstrated a heightened sense of enjoyment to stamp his authority on a top match. Riccardo Calafiori, another who has had an erratic time with injuries, is causing all sorts of issues for opponents. Ben White, whose legs were in bits for a while, is rampaging up and down the right.Without niggles, this squad are capable of new gears. Nobody knows how long this fitness optimism will last — it probably won’t — but while it does, that is Arteta’s plan. “We have some great players, and we really believe in them. Can they improve? Yes. They can have another version of themselves that is even better than anything that we’ve seen. That is the objective we have.”Boring Arsenal? Hardly. This was a revved-up Arsenal playing sharp, snappy football, and they possessed the assurance to crack on with their plan even though they went behind inside two minutes to Morgan Rogers’ smart finish, and had their work cut out being mindful of the danger Chelsea posed on the break. Arsenal maintained their composure and had significant variation in the ways they tried to engineer chances.Last season’s team might have been struck by nerves. Last season’s Emirates crowd might have chewed their fingernails and been nauseous. But things feel different here now, as exemplified by Odegaard’s insatiable creativity and infectious desire.Havertz was similarly engaged. He equalised midway through the first half after picking up the ball on the right flank, jinking back onto his left foot to drive past two opponents and drilling low into the near corner. It was a goal that reflected how he is always driven to prove his worth against his old team.He and Odegaard were clearly on the same wavelength. The combination did the damage for the winner five minutes after half-time. Arsenal broke through Havertz, Calafiori and Christos Tzolis along the left side. The latter carried the ball inside and passed into the danger zone. Havertz’s dummied backheel befuddled Chelsea and Odegaard was perfectly placed to pick his spot past Emi Martinez.Havertz and Odegaard together were crucial for Arsenal against Chelsea (John Walton/PA Images via Getty Images)The contrast between happy Odegaard and the player who didn’t look right for much of the past couple of years is stark. He suffered. Physically and emotionally. Ankle. Illness. Shoulder. Knee. Muscle injury. These issues kept coming. At the same time, Havertz and Bukayo Saka had their own long spells out requiring surgery and rehab. Odegaard also had to contend with criticism about his suitability to be captain — including strong words from one of the finest ever to wear the Arsenal armband in Tony Adams.For a perfectionist, as the Norwegian is, all those imperfections one after the other took a heavy toll.The turning point appeared to come at West Ham in a critical match on the title run-in last season, when a moment of inspiration forged an invaluable win. He sank to his knees and shook his fists in what looked like a very personal moment of vindication. Then came a Premier League title victory and an energised World Cup. From the first day of pre-season, he has behaved like a man intent on seizing the moment.“He demands so much of himself; he wants to be the best at everything and perfect at everything,” Arteta observes. “He’s fit, he feels confident — one of the highest that I’ve seen him, and he has a point to prove from last season after missing so much football. Kai the same, Bukayo the same. We missed so many attacking players last season for long, long periods, and when you start to feel the chemistry they have between them and what they can produce, it’s great.”Arsenal had to marry defensive intent with the attacking expression they strived for. There were standout moments for Ezri Konsa with a roaring tackle on Rogers, and Gabriel for a trademark block. Behind everyone, the hugely-secure David Raya was impeccable, and his wondrous fingertip save to deny Estevao was as stylish as anything else his team-mates produced.It ensured a compelling, knife-edge match ended with Arsenal the sharper.