[Ernst]

I'm not sure of the vendor, but for our tournament "uniform", we tend to follow a schedule:

Thursday: Retro shirt
Friday: Current year tshirt
Saturday: Current year polo

It's important to look good on Saturday for the extra people that come (parents, sponsors, school representatives, etc.) but some people just prefer the tshirts or sweatshirts for the less important days. The downside is that our team is wearing different colors every day (all kinds of blues and golds on Thursday, blue tie-dye on Friday, and navy blue with a hint of yellow on Saturday).