If you kept yourself fit and were in a weight where there was loads of other fighters then you could be fighting up to 15-20 times a year potentially if you wanted to.
We have had boxers who have been competing for 10 years who have had 50 bouts and some who had 500. It all depends on the boxers style and success in the ring.
There really is a straight answer. The number depends on the talent, skill and level of competition in which a boxer competes. Five a year is reasonable for an average amateur. If you are competing at a national or international level you may do 5 per month.
If you are trying to go pro after an am career then as much as you can find. The Amateurs are for fine tuning your skills and getting experience for pro boxing. If you are just doing it for a hobby then do whatever you want.
Straight answer.....5! Lol. Just pick a random number. Why not 3 or 4? Maybe he could manage 6 a year or even 7 if he tried! There's too many variables to give a straight answer, particularly when you have no clue about the person you're responding to. Hence my original response.
I am basing my answer to his question upon my 42 years of experience with boxing. If you took the time to read my answer to him instead of looking for something to argue about. You would have seen that I said there are variables involved that would effect that number. You would have also seen that my numbers are an average based upon my experience.
