Jose Mourinho, whose side beat West Ham 2-0 on Friday and play Southampton on Sunday, believes his side have more creativity this term than last.
"We are a much better team when we have the ball," Mourinho said.
"The challenge this season was to bring that creativity, that dynamism, without losing the good defensive qualities of the team.
"At the beginning of the season there was a little bit of conflict between these two ideas
It was difficult to have a clean sheet.
"In this moment we have a good balance."
The Hammers, who began Boxing Day in fourth place, have been transformed since being criticised by Mourinho for playing "football from the 19th century" last season and joked on Twitter they had arrived at Stamford Bridge by horse and cart.
Yet Sam Allardyce's men sat back and were overrun by Chelsea, who broke the deadlock through Terry's first-half tap in
It was his second goal in two games.
"He always had that (goalscoring ability)," said Mourinho, who made Terry captain during his first spell.
"He's full of confidence
I see my John of 2004, 05, 06.
"I only see a difference when I see his twin (daughters) when they go to the training ground because they were born in that period and now they are running and kicking balls."
Chelsea were comfortable winners, but it might have been more straightforward had they added to Terry's opener before the interval.
Adrian saved well from Gary Cahill and Branislav Ivanovic went down in the box, angering Andy Carroll and West Ham.
Hammers boss Allardyce said: "I thought he went down looking for a penalty.
"They try and make the referees' mind up for them
We all know that staying on your feet does not get rewarded if you're fouled
We all know that."
Allardyce was reluctant to comment further, adding: "I'm not paying any more money to the FA."
Unsurprisingly Mourinho felt Ivanovic deserved a spot-kick.
The Blues boss said: "On television it looks a penalty I think the other guy grabs him."
It was left to Costa, with his 13th of the season, to complete Chelsea's ninth win from nine home games.
Their success has been based on hard work, which continued after the match.
Instead of training twice on Saturday, the players opted to train immediately after the Hammers victory to prepare for Sunday's trip to Southampton.
Some had a recovery session, others a more strenuous workout.
Mourinho said: "They were crying so much in the dressing room I decided to make a change."
West Ham on Sunday face another test of their European ambitions at home to Arsenal after disappointing Allardyce with their first-half showing.
"I'm angry with the first half, the way we approached the game," said the Hammers boss.
"We got better at the start of the second half and then gave a stupid goal away
We created our best chances towards the end of the game
That was too late, and we didn't take any of them."
Source : PA
Source: PA