Doesn't matter, as long as they are quick and athletic, and know how to use their body.
I always liked big horses, until I got my little mare. I love her! But I loved my big horses when I was running them, and would go back to a big horse if the right one came along. My colt that is starting is a pretty good size, and I'm fine with him also.
She has a really different style, not as fast in between, but she can get around a barrel fast with almost no pocket. He needs a bigger pocket, but has a lot longer stride in between.
My best speed horse was a 14.2 grade paint. I have also ran a 15, 16, and 16.3. They were all good in their own way, however I found that the 16.3 horse was a bit clumsy on the turns. It all depends on the individual...I mean I have seen some wickedly fast and agile ponies along with some insane and aggressive strides on some big ones. I agree with quikchik in that it doesn't matter except that they are quick and athletic.
The holy grail is to spend less time making the picture than it takes people to look at it.
Depends on the size of the arena. Bigger horses tend to do better in a larger pen where they have to run more. Small horses tend to do better in a smaller pen where quick and catty will shave of seconds. Most horses in the barrel racing at the NFR are the second type.
Only two emotions belong in the saddle: One is a sense of humor. The other is patience.
well i know size doesnt really matter but the smaller the horse the closer to the ground they can get and usually the tighter turns and the space between the ankle and the knee should be shorter than the space from the knee to the shoulder