The seeds of Chelsea's Premier League title triumph were sown at the end of their dismal 2015-16 campaign, former assistant coach Steve Holland has revealed.
Incoming manager Antonio Conte's mid-game switch to a 3-4-3 system during Chelsea's 3-0 loss at Arsenal last September was widely identified as the pivotal moment in their season.
Holland says discussions about the tactic between himself and Conte began shortly after Chelsea had slid to a disappointing 10th-place finish the previous campaign.
"Antonio said to me at the end of last season: 'I think the team can play 4-3-3 with wingers wide. I also think they can play 4-4-2 with wingers wide,'" Holland said.
"Then he asked me how often they'd played with three at the back in my time. I said: 'Never. Chelsea have never played three at the back.'
"He said: 'I think there is a 3-4-3 there as well with the players we have, but because they've never done it before, it's not going to be the first thing I visit.'"
After starting the season well in a 4-3-3 formation, Chelsea ran aground, drawing 2-2 at Swansea City and losing 2-1 at home to Liverpool, at which point Conte decided it was time to act.
"We won the (first) three games, though the performances weren't always fantastic," Holland, now England assistant coach, told reporters at England's St George's Park headquarters in Burton-on-Trent.
"Then we had the two games you're talking about. He decided more or less at half-time of the Arsenal match that we've done this, we've done that, it's time for this.
"The rest, as they say, is history."