Even though we have hit the quarter mark of the season, it's still not always apparent whether unexpected performances are signaling a legitimate change in skills.

A couple of weeks ago, I went through the exercise of separating the hitters who appear to have taken real steps forward -- or backward -- from those who are still the same players they were before, even if their surface stats suggest otherwise. This time around, I'm putting some starting pitchers under the same type of scrutiny.

None of the pitchers featured here has performed the way his recent track record would have foretold, and some of them have departed from their norm dramatically and consistently enough to deserve to be viewed differently than they would have been just a month and a half ago. Others have merely created a very convincing mirage, but a little exploration shows that they are likely to return to their more typical form going forward.

Will fast-starters like Ervin Santana and Josh Beckett continue to be pleasant surprises or are they merely sell-high candidates? Is it too soon to downgrade our expectations for disappointments like Chris Archer and Shelby Miller? The separating of the flukes from the real deals begins now ...

Pitchers with Increased Value

Jon Lester, Red Sox: After three straight years in which Lester fell short of a strikeout per inning and a 10 percent swinging strike rate, I figured his days of being a strikeout pitcher and must-start Fantasy option were over. Lester's curveball had ceased to be as effective at inducing whiffs, but so far this season, he's been getting more swings and misses on it again. He has also built on the gains he made in control last season, throwing 65 percent of his pitches for strikes and walking 2.1 batters per nine innings. With just one poor start out of his first eight, it's safe to say that Lester is back and needs to be started every week.

Ervin Santana, Braves: Because Santana has been inconsistent throughout his career, it's taken me awhile to warm up to what he has been doing this season. It's been six years since he has even been close to being a strikeout-per-inning pitcher, but I'm starting to think that his current 9.5 K/9 ratio is sustainable. Santana is getting whiffs on an astounding 16.1 percent of his pitches, up from 10.5 percent last season. He is throwing his changeup more often, and more important, he is throwing it more than 1 mph slower while throwing his four-seamer a little harder, according to BrooksBaseball.net. That has resulted in a higher rate of whiffs on both pitches. Though Santana is in what would normally be the post-peak period of his career, he appears to have broken through to another level -- one in which he can be trusted to start every week.

Nate Eovaldi, Marlins: Remember how frustrating it was that Eovaldi threw so hard yet allowed so much contact? Maybe you don't, because he's been so much better at missing bats this season that his past struggles seem like a distant memory. With a 10.6 percent swinging strike rate, he's not in Santana territory, but he's actually been a little better at avoiding walks and clearly superior at inducing grounders than his Braves counterpart. Like both Lester and Santana, Eovaldi has been consistent, as he has yet to have a truly bad outing. The magnitude of Eovaldi's improvement, along with his early-season consistency, makes him easy to trust, despite his past disappointments.

Pitchers with Decreased Value

Shelby Miller, Cardinals: Even with a 5-2 record and a 3.22 ERA, Miller is the 63rd-ranked pitcher in Fantasy points in standard CBSSports.com leagues, and frankly, he's lucky to rank that high. Given his 95 percent ownership rate and 62 percent activation rate, many owners appear to be expecting an imminent turnaround, but Miller is offering no such assurances. His control is consistently abysmal, and that's reflected in his 5.4 BB/9 ratio and 60 percent strikes thrown rate. Batters have learned to lay off Miller's offerings as he has the eighth-lowest swing percentage in the majors (according to FanGraphs.com). That has resulted in dramatic drops in his K/9 ratio (from 8.8 to 6.7) and swinging strike rate (from 10.6 to 7.5 percent). If not for an unsustainable 86 percent strand rate, Miller's ERA could be in the upper 4.00s or higher. He is a must-bench in nearly all mixed leagues and droppable in some shallow formats.

Ubaldo Jimenez, Orioles: Jimenez has been on a roll in May, having allowed only one run 19 2/3 innings, and a 20-to-5 strikeout to walk ratio over that span would seem to support his success. Half of those Ks occurred in one start against the strikeout-prone Twins. Take away that start, and Jimenez has gotten whiffs on seven percent of his pitches this month, and on only five percent for the season. While he has been a little more deceptive recently and also made modest improvements in his control, Jimenez is nowhere close to the form he showed in the second half of last season, when he struck out 100 batters in 84 innings with a 1.82 ERA. After a month and a half of largely unimpressive peripheral stats, it's time to stop waiting for Jimenez to recapture last year's glory. While his mini-streak is still intact, Jimenez is actually a sell-high candidate.

Jake Peavy, Red Sox: As a flyball pitcher prone to allowing the long ball, Peavy hasn't profiled as someone you would target for help with ERA, but he appeared to have a good chance to improve on last season's 4.17 mark. Peavy did in fact shave some points off his ERA after getting traded from the White Sox to the Red Sox last July, and he continued to be a solid contributor to the WHIP category over the course of last season. None of that has panned out this season, as the one-time control artist suddenly can't find the strike zone. Peavy's loss of control hasn't been as dramatic as Miller's, but with four or more walks in five of his eight starts, he seems to be suffering from more than just a mild slump. Since Peavy is still merely an average strikeout pitcher and a worse-than-average home run risk, he can be dropped in at least one-quarter of the 81 percent of leagues in which he is currently owned.

Pitchers with Unchanged Value

Josh Beckett, Dodgers: After two seasons with ERAs on the wrong side of 4.50, Beckett seems to be enjoying a renaissance. He finally earned his first win on Tuesday, but he has allowed more than two runs in just two of his seven starts, compiling a 2.38 ERA. Even more impressive is Beckett's 1.06 WHIP, but both that and his ERA have been helped by hitters batting only .135 on ground balls against him. Even if the Dodgers had a great infield defense -- and they don't -- it would be nearly impossible for him prevent so many ground ball hits. Beckett is getting strikeouts and whiffs at above-average rates, but he did that last season, too. Limiting contact is not enough for Beckett, who continues to be vulnerable to home runs and mild control issues. While he could finish with a sub-4.00 ERA, he's not showing discernible improvement in his skill set, so Beckett is still not a trustworthy pitcher in standard mixed leagues.

Mike Leake, Reds: After a mediocre showing in his first three seasons, Leake took a step forward last year, getting his HR/9 ratio under 1.0 for the first time in his career and posting his first sub-3.50 ERA. Leake has improved his stats further this season, shaving his ERA from 3.37 to 3.09 and his WHIP from 1.25 to 0.99. The one-time first-round pick has long been stingy with walks, but is he ready to become the next Kyle Lohse, perennially helping owners with WHIP if not with strikeouts? It seems unlikely as Leake looks primed for regression in two areas. He has yet to allow a home run at Great American Ball Park, but prior to this season, he has yielded 55 of his 89 home runs at home. Leake has also limited opponents to a .167 batting average on grounders, which is not as extreme as Beckett's mark, but smacks of good luck nonetheless. Though Leake is getting grounders at a career-high 57 percent rate, that alone won't be enough to elevate him above last season's level.

Francisco Liriano, Pirates: Liriano may have won over some owners with a strong six-inning start at the Brewers on Wednesday, but there were no major sources of concern even before that outing. He's never been a big strike-thrower, and his 62 percent strikes thrown rate is not alarming, if not especially good. Liriano is still getting whiffs at an exceedingly high rate (15.7 percent, to be exact), and he's also still very good at getting ground balls. In other words, he's the same pitcher he was last season, aside from a lower foul ball rate that might have played a role in his increased walk rate (4.1 BB/9). At this point in the season, that is probably just noise, so owners can trust Liriano just as much as they did in 2013.

Chris Archer, Rays: Archer's popularity is waning quickly, as he has been dropped in 12 percent and benched in 39 percent of our leagues over the last two weeks. Over that time, there's no doubt that Archer has not pitched very well, as he has demonstrated poor command. Archer may have already frayed the nerves of owners before that, as he finished April with a 4.11 ERA. He pitched better than that stat would indicate, as he walked five batters in 30 2/3 innings and held opponents to an .091 Isolated Power. And Archer's command issues have mostly been limited to two of his last three starts, and that's not enough of a slump to justify a downgrade.

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