We're two months into the season, which means that some (but not all) pitching statistics are starting to gain at least a little bit of meaning. Maybe some players have had poor luck to begin the year, or maybe someone is walking more hitters than they normally would, but other times, pitchers are just that bad. One way of taking a look at this is to check out the quality of the opponents that a pitcher has faced.
The Pitcher's Quality of Opponents report shows you what a pitcher has allowed for average, on-base and slugging rates, but also tells you how those hitters have done against the rest of the league. That way, you can see if a pitcher is struggling against more difficult opponents (or giving up a lot of hits against competition that isn't that intimidating). Maybe someone has a higher ERA than you are used to seeing, but it's because they have been facing difficult opponents for two months that have, as expected, raised their batting average or slugging against.
For the purposes of this piece, I popped the information from the report into a spreadsheet, then checked to see what the difference in the OPS allowed and the quality of opponent's OPS was—that way, we could see who is exceeding/below expectations the most in regards to performance versus quality of competition.
Currently there are 98 pitchers with at least 50 innings pitched, and there's a large range of failures and successes relative to the quality of opponents. Ben Sheets has an ERA of 5.04 right now and a SIERA of 4.56, so you would think things may improve for him a bit in the future, but there are reasons to think otherwise. First off, his .319 BABIP is high, but not especially so (though for the park and defense he's dealing with, you would think it would be better). His problems have been mostly of his own design. His opponent's quality of OPS is 730, which ranks #35 amongst pitchers on the list, but his OPS allowed is 851, the third-highest rate. This is largely due to his walk rate (4.4 UIBB/9) which has produced an opponent on-base percentage of .360. If he can cut the walks (his career rate is 2.1) then he'll be useful, as he'll have a much better chance of both improving his SIERA and meeting its expectations.
Joel Pineiro's reintroduction to the American League hasn't gone that well—he currently sports a 4.95 ERA despite an improved strikeout rate—but there's reason to be optimistic going forward. Pineiro has faced the most difficult opponents of anyone so far, as their cumulative OPS is 770. Allowing a line of .282/.331/.452 makes a lot more sense when you see that the hitters you have faced have put up a .263/.345/.425 line against everyone else anyways. Using something that's a little more neutral context wise, SIERA has him at 3.83, so he's pitched better than his ERA indicates, he has just had to face stiff competition thus far. He's no ace by any means, but we should see improvements to his strand rate and his homer rate as the season goes on and his luck starts to change as far as lineups he faces goes.
On the opposite side of things, some pitchers have just been ridiculously filthy in the early goings. Ubaldo Jimenez's opponents have an OPS of 722, but he's held them to the 500 mark. Even with Boston's early defensive problems, Jon Lester was able to hold his 741 opponents to a 602 showing—chances are good he can continue to outpace his opponents now that the defense is back where it needs to be. You worry about the Gio Gonzalez', Doug Fister's and Jon Garland's of the world a bit when you see how much they are beating their opponent's quality OPS by, but all of those pitchers are in front of top-notch defenses and in parks that help them succeed (and Garland's success has already been covered recently, to boot). Sure, if they have a change of scenery you may not be as interested in them, but abusing their context to the same extent their current employers do is not against the rules, and is in fact encouraged in fantasy baseball.
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