so the talk last night was "what is considered a full book" on a barrel stallion?  50? 60?  Whats considered A LOT? 100?

Is  it usually the same for cutting horses ? race horses? other perforrmance horses?  

just curious, no wrong answer. 

15-30 is average for even a quality stallion.  More than 50 is a healthy book.  More than 100 is outstanding in some regards and too much in others.  Stallion owners decide how many is full.  It might be 5 or 200.  So when they brag the the horse has a full book, they are saying "get it while you can".  Some think it is neat while others roll their eyes.  You be the judge on if you are impressed by that statement.  

I believe the stallions owners typically set the book limits for their stallions, and it seems to differ for every breeder. If a stallion has fertility problems, the owners will usually have a smaller book. The same can be said for a horse that is in competition and may be on the road a lot during breeding season. Also, just because a stallion bred "over 100 mares last year!" doesn't mean he got all of them in foal, or will be having 100 foals the coming spring.

Thanks that makes complete sense.  Is it the same for all performanace horses and race horses - i would think as well