Hey there, right now I happen to be reading "Gazehounds and Coursing" by Salmon. While he doesn't rank our RRs with the best dogs for coursing, nor spend as much time on the detailed description with respect to coursing (one paragraph versus approximately three pages per other breed), he does mention RRs as a possible coursing hound. "Does the straight ridgeback have enough speed for hares, fox or coyote in the open field? I'd certainly like to see a good one at work."
This may or may not help, but for pure speed he seems to think the whippet is the fastest (500 yards or less), with the greyhound the next fastest over that distance (up to one mile, but better at 1 mile), the saluki the fastest over one mile, i.e., it has almost the same speed, but better endurance than the greyhound.
He also mentions the fastest dogs have double-suspension gallop (greyhounds, whippets, salukis, cheetahs, jackrabbits). I thinks our RRs run this way also (though I could be wrong, this is simply from analyzing the photos that I have taken, or seen of RRs in full flight). From what I can gather about the physiology of RRs, the deep, but not too broad chest is great for endurance, and the strong hindquarters should put them up there for speed.
It's my feeling that because of what they were bred for, and how they run, they would be great at doing what a saluki can do, but not as quickly.
JC ran with a whippet today, that was fun.
Cheers,
Mike