I know, I know...but bear with me

For a track day tyre, which provides the most grip?
The reason I am asking is, that on our usual trackdays there is this guy running R888 and he just seems to have more grip than I have on my CR500. The CR500s are only a year and a half old, so I don't think they have gone off.

Hi Bo
The 888's will be much better than the CR500's on a dry track.
But the Yokohama 48's are a better tyre than the 888's.
I do favour the Yokohama or Kumho for fast road and track use.

And then there are the slicks