It seems that my 1 in 76 frames comment in the Steller Blur notes (currently above but will be gone when this rolls over to the 2010 News page) has provoked a number of "thank yous."
Why? Because it appears that some of you (used to) think that pros just go out and produce 100% keepers. A good pro will generally have a higher keeper rate than a good amateur, but it's still not 100%. And that's for "normal" photography. Throw in an animal moving randomly and an attempt to do something aggressive like pan blur, and the keeper rate for even the best pro will be low. If I recall correctly, Art Wolfe used to say that he exposed hundreds of rolls of film (thousands of frames, perhaps more than ten thousand) to get the 125 images for his book Rhythms of the Wild.
Once when Galen Rowell and I came back from one of his photo tours I discovered that I had exposed the same number of rolls of film as he had during the three weeks (we were dropping our film off at New Lab since it was on the way home for both of us from the airport). That provoked me to ask him how many keepers he thought he had. For 120 rolls of film his response was "maybe a 100 that I'd put in my A files; probably less." So 1 in 36 at best case, though that number is a bit deceptive. Galen often made in-camera duplicates when he thought he had one of those images he had a great image. Still, the point remains: pros don't produce 100% keepers.
Indeed, I'd tend to say that anyone who is producing 100% keepers isn't pushing themself very hard. I'll bet that they've "perfected" some basic image and just keep repeating it. I actually don't like it when I come home and find lots of decent images, but nothing that shows that I pushed myself. As Susan Sontag suggested in her book On Photography, time works against photographers. The first person to take a picture of Half Dome, for instance, had an advantage over the rest of us: at the time, almost no one had actually seen the rock in person and thus even a representative photo was a "keeper." Over the years, it gets more and more difficult to take a unique photo that includes Half Dome, as the others that came before you have polluted the waters with virtually every easy variation. It's no longer good enough to just frame Half Dome well plus get the exposure and white balance right, even in dramatic end-of-day light: it's not a "keeper" any more because it's been done to death.
So don't be afraid to try new techniques and fail at them. I failed 75 times before I got something I liked. Actually, I failed 450 times and got 3 images I liked. And yes, it took me longer to get the first interesting image than the second or third. Practice works. That's why I do it as much as possible.