My two best catch dogs (lurchers), were 36 kgs, 26"" tts and 29"tts respectively, and I'd say the 26" dog was 'marginally" faster over the first 30-40 yards, just.
In fact, if you saw the 26" dog before he ran, you'd think, as did many, he wouldn't be very quick at all.
I'll just say CARL WILLIAMS, and SHOCK.