Proving that you never know, the painting above was accepted into the 2011 National OPA Exhibit. This year, I submitted 2 entries, feeling more confident about a larger, 24 x 24 piece, but this one was selected! I think it might be the smallest painting in the entire show. Devin Galleries in Coeur d'Alene, Idaho, is hosting this year's Oil Painters of America National Exhibit, June 10th - July 9th; it's the 20th anniversary for the OPA National Exhibition honoring representational/traditional oil painting and painters. I'm proud to be in the exhibit and to be a signature member of this organization.
Entering national shows is a nice resume enhancer, should an artwork be selected -- and, as Kevin MacPherson says, no one ever knows about your attempt should you not make it. I submitted entries to OPA for 5 or 6 years before I had the first one accepted in 2006. I don't paint for these shows (trying to create a "winner," or a "good painting," typically is not a way for me to succeed). From available work, I usually pick one or two to submit which I think might have a chance. Judging is by its very nature subjective, and what I think are sure bets often don't get the nod. When it works, though, it's a nice thing!