Diego Costa is a new man, and Antonio Conte is the reason

Diego Costa has been in incredible form this year, and he's back to being one of Chelsea's most important players. He's not just scoring goals and playing well though: he's staying out of trouble, and he even somehow looks... happy?

Costa scored his 12th goal of the English Premier League season on Sunday against West Brom. It gave Chelsea the victory, and took them three points clear at the top of the table. It was everything we've come to expect from the Spanish striker when he's at his best: incessant work rate, a refusal to give up on any play, and then a quality finish to cap it all off.

Afterwards, David Luiz got a video of him celebrating in the locker room, happy as a clam. Dancing, even.

Since the arrival of new manager Antonio Conte, Costa's looked like a completely different man. Not only is he at the top of his game, he's doing it without the typical squabbling and strife that previously accompanied him every time he stepped on the pitch. Costa's 76th minute strike against West Brom was his fifth in six games, and it puts Chelsea two matches off their all-time consecutive wins record of 11 in a row. Maybe more impressive than those numbers? He hasn't gotten a yellow card since September 24th, in the 3-0 loss against Arsenal. It's his best disciplinary run in a full six years.

It's unclear what Conte's done to Costa to mellow him out. Whether they're doing hot yoga and meditating every day, attending anger management classes together, or Conte just switched his frontman's coffee with decaf, it's working. The 28-year-old's still the same aggressive, in-your-face effective presence he always was, but now he's seemingly doing it without the malicious edge that made him so infamous from the time he arrived in England.

Conte's positive influence on Chelsea has been undeniable. Tactically, his shift to a 3-4-3 has balanced the team out, masked their weaknesses, and played to their strengths. More importantly though, he's imbued his side with a new confidence, determination and unity that was completely lost during Jose Mourinho's last season with the club.

Conte talked about the importance of Costa after the West Brom result, calling special attention to his reborn striker's new mindset.

"It’s incredible that, after the Arsenal defeat, Diego had four yellow cards and was on the edge, and he has continued to stay on the edge,” said the ebullient Italian. “I think he can arrive in January without a yellow card. I hope so.

"Look at the image of Diego against Manchester City [when he played peacemaker in the brawl at the end]. I always tell my players to stay focused on the pitch, think about playing football, doing the movement we tried in training sessions. I don’t like provocation, I don’t like bad attitudes, and I’m trying to transfer this to my players. But I’m very lucky because I have players with great behavior.

"Diego is enjoying this football. He’s showing his passion in the right way. You ask why it happened in the past, but I don’t know. Now I can only talk about his commitment, his work-rate during the games, and it’s fantastic. I want this from all my players. I try to get all my players to think like this.”

It may be psychotherapy. It may be Santeria. Whatever it is, it's working. Blues supporters won't really care, so long as Diego Costa keeps scoring and Chelsea keeps winning.

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