Chelsea manager Antonio Conte revealed he rolled the dice with a formation tweak at Stoke because he was not content to leave the bet365 Stadium with just a draw.
Having started the weekend with a 10-point lead at the Premier League's summit, the Blues were on course for a share of the spoils against the Potters once Willian's free-kick was cancelled out by Jonathan Walters' penalty before half-time.
Conte was unwilling to settle for such an outcome, even with their huge advantage at the top, and brought on Cesc Fabregas with 20 minutes to go - replacing Victor Moses and altering his 3-4-3 system to a back four so he could accommodate his substitute in a central role.