There are many different schools of thought on this, and it comes down to personal preference, and the degree of match's you are shooting. Most shooters would take new to fairly new brass to the super shoot, everyone wants to do there best, and have no excuses why they did bad. Some shooters would not waste good brass on a local club match, with a few shooters, winning nickels, so that makes the first difference. I know shooters that shoot there brass 4 aggs or two entire match's, (Light gun, Heavy gun, 100 and 200 yards.) and pitch it aside for varmint hunting, or small match's, or even sell it to others. I know other shooters that will never throw out a piece of brass no matter what. (One guy I know shoots club match's with brass with well over 100 firings, and he is very competitive.) My personal preference is for a registered match I would like to have fairly new brass, maybe a couple of firings on it. For a club match I fire brass until it gets a click in it, (Click= when you raise the bolt handle after firing it stops at the primary extraction cam, forcing you to pull the bolt up hard.) then I pitch it. I have noticed that brass last longer than most shooters will use it, and have notice little to no accuracy difference between newer and older brass. basically if it makes you feel good do it.