The opinions on this subject vary greatly...
Some people break yearlings, others wait until the horses are 4+
It's generally accepted that the horse should be a minimum of 2.5 years old and have the proper muscling to carry a rider. If the horse is backed at 2.5 years old, it's best to just walk around the ring to teach them basic commands. At around 3-3.5 years old you can begin trotting and cantering, and start some very light jumping work at 4. No heavy work should be done until the horse is 5.
it depends on who you want to train and/or break your horse.
A horse
Break Horse Power
yes it can
507 bhp(Break horse power)
a horse has three after the breaking of limb
Break & Out class is simply 'Simon Says' on horseback. This class is usually seen at playdays/fundays and not regular horse shows.
Nobody can be sure of the very first person to break and train a horse, as it was such a long time ago.
break horse power
Win a race
You probaly could break him/her but at that age I recommend just leaving him/her be.
No,all you have to do is break the horse