Benjamin can feel the difference in John's game. Something's shifted, like confidence, or fool-hardiness. Probably a bit of both. It doesn't change his own play, calculated, cautious, a few moves ahead when he can manage. It's not easy, but it is, perversely, a lot of fun, trying to counter every one of John's moves, trying to save his major pieces, without any hesitation sacrificing the minor ones when needed.
As long as it is clear that it is absolutely necessary.