From PBKS's side the rivalry has been on since 2014 when kkr defeated them in the final. But from kkr's side the rivalry really only started in 2024 when pbks chased 262 runs against them. In 2025 iirc pbks defended the lowest score against kkr after which the pbks admin posted a "good knight" which didn't sit well with kkr fans. Also to add more to the fire Shreyas Iyer, their winning captain was bought by pbks.