This is my first experience with mlb shirts and I must say they are now in my regular rotation I followed what others had mentioned. In that I wasn’t looking for a skin tight or too firm fitting right now. I ordered 3 in assorted colors in size Medium and they fit like a glove. Perfect. Not too small, not to loose. I normally would wear a L which would show a more "athletic fit" taper when used to be high muscle weight Body Mass ratio, wide shoulder small waist build. But I’m recovering from some unpleasant illnesses treatment effects currently and that took a lot of good weight off. Shoulders are naturally wide but chest, back, & arms are now what they were at 15 . So I needed to basically re outfit my wardrobe. These shirts are so comfortable. They absolutely do what they are noted to- wick away excessive sweat. They look nice with a pair of jeans or say, tru-spec, 5-11 type BDU cargos. I like the way they cut through wind when riding a motorcycle. I live in Arizona so it’s hot most of the time but cold or cool still at night until May. These will serve to protect from damaging exposure to Sun/wind on long rides or hikes in summer very nicely.
I was really needing something a little longer for backpacking. Most standard length shirts are fine on me, but when you're backpacking with a fully-loaded pack for extended, long-distance trips, you want longer! You do NOT want your shirt riding up and either bunching up under your hip belt or worse... above it, allowing the belt to chafe you to pieces.

This fit and function of this shirt were terrific! The moisture wicking performed like a champ on a strenuous hike up Springer Mountain, Georgia on the Appalachian Trail, but it also served as a nice base layer, keeping me warm when we would stop hiking, cheap authentic football jerseys to rest, in the lower-30's degree weather with 20+ mph winds.