So people that run a horse that is 16+hh, Do you typically like to give them more of a pocket to help get their big bodies room to get around. I typically like to run more towards my 3rd going to my first and don't struggle there. But for second and third barrel I think I am needing to give him more of a pocket. 

What do you like to do for your big horses. 

This mare is 16-1 at least. The secret is to make sure they are extremely broke and you have control over every foot at all times and that they bend through their entire body. I hope this picture will post, my internet is horrible. Well picture won't load so will link a video. This mare doesn't look like she is running but she has a huge stride and covers a lot of ground. Enjoy the cheering section!

https://m.youtube.com/watch?v=e7eE6N8Sxx0&feature=youtu.be

I do the same thing for my 16.2hh mare as I did for my 14.3hh mare.  The only thing that is different is her turning style.  I didn't pattern either of my mares until they were extremely well broke.

I think it depends on the horse and turning style honestly. I have seen little horses that need more of a pocket then those big 16 even 17 hand ones that you can drive straight to the barrel. I'd suggest video video video and watch them over and over. Trial and error. I just dont think it's a fair statement to say pocket size directly coorelates to horse size.