It took a dominant 11-strikeout, zero-walk performance from Taijuan Walker for the fantasy world to finally take notice of him. I don’t have ownership trend data to exemplify this, but I do have an anecdote: he was available in every league I’m in before the start, and he was owned in every league I’m in shortly after it.

The truth is Walker had demonstrated progress, described here by Eno Sarris, in his prior four starts, notching 27 strikeouts to three walks in 29 innings. Someone who hadn’t been paying attention to Walker probably wouldn’t have noticed: his ERA prior to the recent five-game surge stood at 7.33, and he had completed the sixth inning only twice in nine games. Once a hyped prospect, he looked like a 22-year-old who still needed seasoning to reach his potential.

No longer, as you will probably have to give up an asset of value to acquire Walker from a fellow owner now. The price may not be too steep given his poor ratios (4.94 ERA, 1.39 WHIP), but this is likely the highest they’ll be for the rest of the season.

Walker has been trending in the right direction for some time now, although his progress didn’t really accelerate until June. I investigated other pitchers whose defense independent pitching statistics (DIPS) statistics have improved each month of the year. Fielder independent pitching (FIP) relies on a pitcher’s peripherals to estimate a “true” ERA, so monthly improvements in the statistic can indicate legitimate skills improvements. This is especially relevant for pitchers who started the season slowly: their inflated ratios mask their true skills and/or performance, rendering their perceived values lower than their actual values.

The keen owner capitalizes on such market inefficiencies. We tend to call this buying low in layman’s term, but I don’t know if the two concepts perfectly align. Regardless, these are the kinds of moves that bolster dynasties and spur second-half surges.

For your reading pleasure, I identified seven starting pitchers whose xFIP (expected FIP) has improved every month this season. I considered only pitchers who started at least three games in every month. The list is sorted by the largest difference between April and June xFIPs.

Kyle Gibson, MIN

April / May / June xFIP: 5.70 / 3.93 / 2.95

ESPN / Yahoo! Ownership: 17.1% / 14%

A horrific start to the season (3.1 IP, 6 ER, 0 K, 5 BB) almost doomed him from the start, but Gibson quickly steadied the ship. His ERA fell by more than two runs, from 4.84 to 2.61, from the end of April to the end of May. His ERA is starting to float back up despite his improvements in June. FIP and xFIP disagree about where his ERA should really be this month, as the former is almost two runs higher. However, xFIP adjusts for expected home runs. On June 5, Gibson allowed three home runs to the Brewers; however, he allowed only one home run every two games in all his other starts. I’m inclined to side with xFIP, therefore, which also considers the Milwaukee game an anomaly.

Perhaps Gibson can’t sustain his recent strikeout rate, but his K/9 rate for the season forsakes his true ability. He has demonstrated he can succeed with the classic Tim Hudson approach: few strikeouts, few walks and lots of ground balls. You could consider Gibson a kind of Dallas Keuchel Lite.

Wei-Yin Chen, BAL

April / May / June: 5.20 / 3.69 / 2.51

ESPN / Yahoo!: 25.6% / 46%

Unlike Gibson, both Chen’s monthly FIPs and xFIPs agree on his improvements. However, Chen’s ERA has hovered below 3.00 this season more often than not; his ERA has fairly consistently aligned with his DIPS. Still, he remains unowned in two of my four leagues, all of which are shallow mixed leagues, attesting largely to his bad luck in earning the win — he has earned wins in only two of his eight quality starts this season. He’s also currently in the minors because of not poor performance but for rest; a quirk in his contract allows the Orioles to option him, clearing roster space while he rests.

Chen’s stock is low for reasons largely outside his control. He has won his last two starts, so the window to buy low on him (or add him from waivers) is closing, especially after a very strong 8-inning, 9-strikeout start last week, albeit versus the lowly Phillies.

Chris Sale, CWS

April / May / June: 3.44 / 2.87 / 1.14

ESPN / Yahoo!: 98.9% / 99%

I remember when fantasy owners, including analysts, wondered what was wrong with Sale. Even his xFIP pointed to good things to come. Little did we know the wrath we actually wrought.

Taijuan Walker, SEA

April / May / June: 4.80 / 4.21 / 2.63

ESPN / Yahoo!: 49.1% / 60%

As aforementioned, Walker has had a monster June, and there’s little reason to think the trend of success will suddenly reverse. His lack of command had betrayed his tools, but an increase in first-pitch strikes has compensated for it, getting him to favorable counts more quickly and more often. Also as aforementioned, Walker was a touted prospect. It’s reasonable to daydream about our next Chris Archer or Sonny Gray or Julio Teheran type of breakout.

Wade Miley, BOS

April / May / June: 5.90 / 4.28 / 3.81

ESPN / Yahoo!: 10.3% / 6%

Miley is inconsistent and unreliable, but he has taken strides that should help console panicked Red Sox fans a little bit. His ability to limit damage via home runs has kept him from afloat, but barely. He started walking fewer hitters in May, and now he’s striking out more hitters in June, both developments that should allow him a greater margin for error, which he desperately needs.

Cole Hamels, PHI

April / May / June: 3.81 / 3.26 / 2.02

ESPN / Yahoo!: 98.1% / 98%

Hamels actually had a pretty bad April, all things considered: he walked every eighth batted he faced, yet managed to pitch to a respectable 3.19 ERA. That rate has markedly dropped, and his DIPS have followed suit. Thirty-one years old and still cruising, Ruben Amaro, Jr. must be pleased his prized pitching asset should net him a strong ret– huh? What’s that? Oh, never mind.

C.J. Wilson, LAA

April / May / June: 4.65 / 3.85 / 2.88

ESPN / Yahoo!: 61.4% / 56%

As an Angels fan, Wilson’s remarkable lack of command is incredibly frustrating, and I love to hate him. To my disdain, he is actually pitching well right now and has been for some time, although his ERA forsake his actual improvements. Such are the peculiarities of baseball. Truthfully, he has been pitching well, and although he still walks way too many batters for my tastes, it’s hard to ignore five straight starts of 7-plus strikeouts.