Chelsea captain John Terry has praised the form of his side since manager Antonio Conte switched to a 3-4-3 formation.
The Blues have stormed to the top of the Premier League table courtesy of a run of 11 victories in a row, and could make it a club-record 12 if they beat Bournemouth on Boxing Day.
Terry has featured for just six minutes of that run after losing his place in the side following an injury, but he is delighted with how things are going for the team.
"The formation changed and the manager kind of had it in mind pre-season so we'd done a lot of work tactically on playing three at the back, et cetera," he told Soccer AM.
"We lost the two games, Liverpool at home and then Arsenal away, and the manager's just decided to switch and it's worked. The team's been looking really good, it's been really good to see.
"I think it's taken other teams by surprise a little bit because we've not seen that many formation for so many years in the Premier League."
Chelsea, who are currently six points clear at the top of the table, have won the title on the four previous occasions that they have been top at Christmas.