I get what you are saying though, but that 10FPS on a sunny day sounds very nice for a grandpa trying to get that perfect shot.
While I shoot hockey a lot (my kids play) I never use the burst mode, I'm always single shot. Maybe it's because I play as well, dunno, but I can anticipate the shot and get what I want.
I have had to work on my technique to get those shots. I learned that AI-servo really helps (that's an understatement), I use center point focus, spot metering, shutter priority and I tend to set the ISO, auto ISO hunts more than I like.
The real reason I don't do bursts is I hate having to go through all that crud and delete the non-keepers. I tried burst and found that my keeper rate fell to about 1-10%, closer to 1%. My keeper rate for single shot is 50-90%. So I had a good reason to work on my technique. If you don't made the post filtering then yeah, I've heard 8fps is as "slow" as you want to go.
Good luck with whatever you do, and don't worry too much, you've got an awesome body in the 5DIII. I love mine.
I don't know which body and lens you are using, but your keeper rate in extreme low in burst mode. I did find out, and seen that many more action photographers, use centrum weighted measuring instead of spot measuring. I don't have then problems then that my auto-iso hunts that much.
I'm using the 200mm f2.0 prime (a very nice lens) and the 5DIII (which I also like).
When I'm shooting burst there are all the pictures before and after the shot I wanted that I toss. I'm taking 10ish pictures to get one (and that doesn't always work).
I play hockey and I can anticipate what is going to happen, I know the shot is coming because I see the windup, I've gotten dozens and dozens of nice shots of goals being scored with the puck in midair. All single shot.
If you don't play the game I suppose it would be harder (I sort of feel like being a player is "cheating" when I'm taking pictures, I know where the game is going. I also coach several teams so that probably helps with reading the game). Anyway, for me, single shot results in just as many (or close) keepers and a ton less post processing (which is really delete, delete, delete...).
This is all at the rec/high school/travel level, so it's not a money maker (though I've been offered jobs by the pros, LOL, $25/hour 1099 money, like that's going to pay for my equipment I just do it so I've got pictures to look at when my kids move off to college and for the other parents/kids. So I'm optimizing for the least hassle for me.
If I was getting paid to take NHL pictures then I might play with the burst mode, doing it for fun means I spend too much time deleting.
Nice combo by the way. Not only for sports inside but also for portrait.
I do understand what you mean now by keeper rate. It's keeper rate against the required shot you would like.
For sports it is such a tremendous advantage you can read the sport. In fact for all type of action photography. You are fully right that using continuous mode would give you a lot of photos, which you don't all want to keep. Best advice there for people is to use for a while NOT the continuous mode, but the single shot. Just to reduce the load of generated photos. Also in continuous mode, you need to trigger your camera only when it is needed. You need the correct face expression, the position of ball, or in your case the puck. And that's exactly what you are doing.
Sorry, but thought you needed some assistance for such a high rate "out of focus" which you din't say say but I presumed from your low keeper rate.
The dangers with not using burst though are:
1. AF will miss, with burst at least maybe you got once decent shot in focus out of the sequence
2. you might not handle the AF perfectly in all cases and then once again a burst might at least get one semi-decent shot
3. sometimes a hideous facial expression or arm pops up in some weird position or blocking something critical, you can known the sport as well as a pro and have played it at a high level, but it won't help in these cases, a fast burst might still get one great frame
4. sometimes you want more than one key frame
5. something things go into a wild melee
for some things, like ball on head or bat, you do have to time it yourself, even a 10fps is way to slow
and even for regular things, sometimes your own timing can pick the peak of the peak of a sequence out better than a burst (although once you get to 12fps the burst can often do it as well, plus with 8 or better 10-12 you sometimes want and can get a couple really key frames)