A lot of people, I think, have some grasp of quality of competition. Talk to someone about Toronto or Baltimore and they'll tell you "sure, they aren't winning, but then they have to go up against Tampa, Boston, and New York all the time." It's also an argument in favor of David Price for the AL Cy Young. Price doesn't have the best numbers in the league, but he has had to face the Red Sox, Yankees, and Blue Jays lineups 11 times. It's something people are willing to take into account.
When you hear about quality of competition, though, it's generally only raised when the competition has been tough. You don't hear about it so much when the competition's been easy. And as it turns out, the Rangers' competition - at least on the mound - has been pretty easy, relative to the average.
With one of its statistical reports, Baseball Prospectus allows us to sort pitchers by their quality of competition, calculated as average OPS. The mean in the AL is right around .734. That is, the average American League pitcher this year has faced opposing hitters with an average OPS of .734.
187 pitchers in the AL have thrown at least 30 innings on the season. If you sort them by easiest quality of competition, you get Dan Wheeler at the top - Wheeler has faced opponents with an average OPS of just .704.
But what you notice after Wheeler is the abundance of Texas Rangers. C.J. Wilson shows up. Chris Ray (who has since departed) shows up. Darren O'Day shows up. Derek Holland. Scott Feldman. Alexi Ogando. Dustin Nippert. Colby Lewis. Tommy Hunter. Nine different Texas Rangers - or eight different Texas Rangers, and one former Texas Ranger - appear in the top 20 for easiest overall competition.
When you think about it, this shouldn't come as a surprise. The Mariners have the worst team OPS in the American League by a significant margin. The A's are second-lowest. The Angels have been better, but they're still tenth of 14. The regular season schedule is unbalanced, as teams get to play a lot of games against their divisional rivals, and the Rangers' divisional rivals, by and large, haven't been able to hit.
And it shows up in the results. Texas has a 3.95 team ERA. Within the AL West, it's 3.27. Outside the AL West, it's 4.30. The Mariners in particular stand out as the easiest opponent, having scored just 51 runs in 19 games against the Rangers.
I don't think this is a super huge deal, mind you. I don't think the Rangers' pitching staff is a paper tiger, set to get exposed under the bright lights of the postseason. They have a bunch of quality arms, and quality arms that will remain as such against quality competition. It's just something to think about. The fact of the matter is that the Rangers have spent the year in a light-hitting division, and that division has allowed their pitching staff to appear a bit better than it really is.