By the Numbers: Sizing up the trade market

It has been a month since I culled the top buy, sell and hold candidates from the ranks of Fantasy's starting pitchers, and a lot has changed since the season's early weeks.

Philip Humber perfect game seems like eons ago and Anthony Bass hasn't looked like a wunderkind lately. Meanwhile, Colby Lewis appears as if he is back to his surprising 2010 form, and Wade Miley is getting to be known as something other than "not Trevor Bauer ."

What we see on the surface for these pitchers is not necessarily a bellwether of their future performance. By accounting for the part of ERA that is due to defense and luck, xFIP can be a useful tool for identifying fluky ERAs. xFIP pegs both Humber and Bass as underperformers who should be much better going forward, while Lewis and Miley appear headed for substantial ERA increases. There are reasons to doubt an xFIP-based forecast for some of these pitchers, so a hurler who looks like a clear "buy" or "sell" may actually be more of a "hold" candidate.

So which pitchers belong in which categories? That's the task I'm about to embark on. We'll take a deeper look at these four starters, along with 10 others, each of which is currently a top buy, sell or hold target.

All stats are current for games through Tuesday, June 12.

Top buy candidates

James Shields , Rays (4.06 ERA, 3.38 xFIP): Because Shields' spectacularly poor 2010 campaign is still fresh in many owners' minds, there is fair amount of distrust around him lately. Though Shields was typically drafted to be a No. 1 or high-end No. 2 starting pitcher, he is currently warming the bench in 15 percent of the leagues on It's true that Shields is walking batters a little more often than he did a year ago, but he's also striking them out more often, too. The main thing that is keeping Shields from repeating last season's success is a .190 batting average on flyballs in play that is way out of line with his norms. While more reliable indicators (e.g., strikeout and ground ball rates) have been similar or better than last year's for Shields, owners should take comfort in Shields' struggles being tied to a volatile stat like flyball BABIP. Before that rate starts to shrink, find a nervous owner and see if you can get Shields on the cheap.

Most Traded Pitchers (as of 6/14)
Player # of trades
1. Tim Lincecum , SP, Giants 781
2. Cliff Lee , SP, Phillies 563
3. Jon Lester , SP, Red Sox 488
4. Dan Haren , SP, Angels 433
5. Felix Hernandez , SP, Mariners 400
6. CC Sabathia , SP, Yankees 365
7. Josh Johnson , SP, Marlins 359
8. Yovani Gallardo , SP, Brewers 358
9. Matt Garza , SP, Cubs 347
10. Justin Verlander , SP, Tigers 344

Matt Garza , Cubs (3.99 ERA, 3.51 xFIP): Owners were rightfully concerned when the Astros and Pirates took Garza deep five times over a span of seven innings, but he seems to have put that ugly stretch behind him. In the two starts since then, Garza has restored his ground ball rate to 49 percent, which is just one tick below his season-to-date mark. Even with those starts included, Garza's 3.51 xFIP and 8.4 K/9 rate should be useful to owners in nearly all formats, yet he is currently inactive in one out of every three of our leagues. With so many owners skittish about using Garza, now is the time to snag a legitimate No. 3 option at a bargain price.

Anthony Bass , Padres (4.38 ERA, 3.76 xFIP): Bass' stock has fallen dramatically over the last three weeks, as his ownership rate has plunged from 53 to 34 percent. An 8.14 ERA over his last four starts surely has something to do with his decreasing popularity, and some struggles with command have played a role in his slump. Owners shouldn't expect Bass to be a big-time strike thrower, but he continues to be a reliable source of strikeouts nonetheless. When hitters have been making contact, they have probably been a little lucky, as Bass has allowed a .213 batting average on flyballs in play. Even in his starts at spacious PETCO Park, Bass should expect that rate to recede, so if you're buying him now, you're likely to get stats better than his current 4.38 ERA and 1.32 WHIP.

Dillon Gee , Mets (4.42 ERA, 3.44 xFIP): Because he has been homer-prone in the minors and walk-prone in the majors, I have been slow to warm up to Gee this season. However, with surging swinging strike and ground ball rates and improved command, Gee is looking as if he is in the midst of a legitimate breakout. Apparently, I haven't been alone in my skepticism, as Gee is still unowned in 60 percent of our leagues. Given that he has fairly normal home run and line drive rates, it seems unlikely that his strand rate will continue to linger below the 70 percent mark (his current rate is 69 percent). Once he starts leaving a few more runners on base, Gee profiles as a pitcher that you can use at least some weeks in standard mixed leagues.

Hector Noesi , Mariners (5.99 ERA, 4.76 xFIP): Noesi allows a few too many walks and flyballs, but he's not without his uses. His flyball tendencies play well at Safeco Field, where he has a 3.62 ERA and has allowed just four of his 14 home runs. His .226 BABIP is a little too good to be true, but favorable popup and line drive rates should keep it well below average. Because he is homer-prone, Noesi probably won't post a league-average strand rate in the low-to-mid 70s, but his 56 percent rate is undeservedly low. While he's not on the level of a Jason Vargas , who can be used in standard mixed leagues when the matchups and venues are right, Noesi should be owned in far more than nine percent of our leagues.

Top sell candidates

Ryan Dempster , Cubs (2.31 ERA, 3.62 xFIP): Given his history, few owners are likely to expect Dempster to own an ERA in the low-2.00s deep into the season, but the question is how high will it rise? To look at his lower-than-normal walk and homer rates, it would be reasonable to think that Dempster might be able to do better than the 3.70-ish ERA that xFIP usually predicts for him. However, for the second straight year, Dempster is seeing some erosion in his ground ball rate. He's also getting a lot of help from highly favorable strand (81 percent) and BABIP (.246) rates. xFIP indicates that Dempster could have an ERA in the mid-3.00s, and if he reverts to his wilder ways, you could be stuck with a mediocre pitcher on your hands.

Colby Lewis , Rangers (3.13 ERA, 3.69 xFIP): Lewis' activation rate has been climbing steadily over the past month, while his ERA has been headed the other way. If you're an owner who is starting Lewis every week, you're counting on him to avoid homers like he has done over his past six starts. He's allowed only four home runs over a span of 42 2/3 innings, but Lewis is barely less of a flyball pitcher than he was earlier in the season. Even without an increase in his recent home run rate, Lewis is due for more runs to cross the plate, as his 79 percent strand rate is suspiciously high. Of course, it's reasonable to expect that there will be more flyballs reaching the seats, so the shock to Lewis' ERA and strand rate could be a dramatic one.

Mark Buehrle , Marlins (3.41 ERA, 4.16 xFIP): Buehrle is getting batters to swing more frequently at his offerings outside the strike zone, so his walk rate (1.3 BB/9) is now barely visible without a microscope. That doesn't fully explain his 3.41 ERA, though. Hitters are connecting on many of those errant pitches, so Buehrle's K-rate is actually a little lower than last year's. He's been rescued by a .142 opponents' batting average on grounders, and the Marlins' infield defense simply isn't that good. For someone who offers little help in the strikeout category, Buehrle doesn't do enough to prevent hits and runs to merit an 82 percent ownership rate. His ERA may not crack 4.00 as xFIP suggests it will, but now is the time to deal Buehrle before his WHIP, currently at 1.13, loses some of its luster.

Hiroki Kuroda , Yankees (3.46 ERA, 4.17 xFIP): With a sparkling 0.82 ERA over his last three starts, Kuroda just may be turning his first season in the Bronx around, but it could also just be an enticing mirage. Kuroda's biggest challanges have been to keep home runs in check and to throw strikes consistently. Over his last three games, Kuroda's ground ball rate has actually dropped slightly, and his strikes thrown percentage of 61 percent is exactly what it was over his first nine starts. Given those trends, it's hard to trust what he's accomplished against the A's, Tigers and Mets in his recent outings. Factor in unusually favorable strand and BABIP rates, and it looks like an opportune time to start shopping the ex-Dodger.

Wandy Rodriguez , Astros (3.27 ERA, 3.93 xFIP): Rodriguez has made remarkable gains in his efficiency this season. While the ability to go deep into games has endeared him to owners in Head-to-Head points leagues, his sagging strikeout rate more than cancels out the minimal gains he's made in innings per start. Earlier in the season, it was easier to buy into Rodriguez's high strand rate, but with his home run and line drive rates climbing over his last half dozen starts, his 3.27 ERA is looking more and more like an illusion.

Hold these pitchers

Jeremy Hellickson , Rays (2.65 ERA, 4.49 xFIP): I have spent much of the past year in disbelief over Hellickson's ability to prevent hits and runs, but with an uncanny ability to avoid hard contact, his stats are looking increasingly legitimate. Not only can Hellickson sustain favorable strand and BABIP rates, but he's become a better pitcher against left-handed hitters. Given his mediocre strikeout, walk and ground ball rates, it would be easy to dismiss Hellickson's 2.65 ERA as a fluke (trust me, I know from experience). xFIP certainly does, but Hellickson's year-and-a-half of major league experience suggests that it's a mistake to view him as a sell-high candidate.

Wade Miley , Diamondbacks (2.53 ERA, 4.07 xFIP): Miley's rate stats are not much different from Wandy Rodriguez , but too many Fantasy owners see Rodriguez as the superior pitcher. While Rodriguez is still owned in 90 percent of our leagues, Miley's ownership rate clocks in at a more modest 75 percent, even though xFIP doesn't see a significant difference between them. Miley actually has the lower ERA and WHIP, and because he has a history of low line drive rates and currently has a good infield defense behind him, Miley has a decent shot at maintaining his stats at a level not far from where they are now. You might regret it if you sell Miley now.

Philip Humber , White Sox (5.92 ERA, 4.45 xFIP): With a 62 percent strand rate, it may look as if Humber's 5.92 ERA is unnecessarily bloated. However, as Humber has become increasingly reliant on his slider, he has seen his flyball rate soar. That's been a bad development, particularly in Humber's home starts. (Note that Humber's perfect game occured at Seattle.) At U.S. Cellular Field, Humber has allowed 10 home runs over 37 2/3 innings, while he has coughed up just two homers in 24 2/3 road innings. Maybe Humber would be worth buying if you planned on benching him for his home starts, but that strategy could backfire. With the success of Jose Quintana and the imminent return of John Danks (shoulder) from the disabled list, Humber may have already blown his chance for redemption, as he could be headed to the bullpen.

Mike Leake , Reds (4.97 ERA, 4.20 xFIP): If Leake's poor strand and BABIP rates haven't convinced you that he is a good buy-low candidate, then his recent string of effective starts might have done the trick. However, those unseemely strand and BABIP rates are probably more legitimate than the 2.84 ERA he has posted over his last five outings. In those starts, Leake has continued to allow line drives at a high rate, but he hasn't payed the price in the form of an unusually high BABIP rate. Leake has also been throwing fewer strikes and getting whiffs at a lower rate during his hot streak than he was beforehand. Now is not the time to trade for Leake, and he may not even be worth a waiver claim outside of NL-only leagues.

xFIP: Also known as Expected Fielding Independent Pitching. It is an estimate of what a pitcher's ERA would be if it were based on factors that a pitcher can control, such as strikeouts, walks and flyballs. xFIP is a derivative of FIP, which was developed by Tom Tango.
Runs Created per 27 Outs (RC/27) -- An estimate of how many runs a lineup would produce per 27 outs if a particular player occupied each spot in the order; ex. the RC/27 for Miguel Cabrera would predict the productivity of a lineup where Cabrera (or his statistical equal) batted in all nine spots; created by Bill James
Component ERA (ERC) -- An estimate of a what a pitcher's ERA would be if it were based solely on actual pitching performance; created by Bill James
GO/AO -- Ground out-air out ratio
GB/FB -- Ground ball-fly ball ratio
Batting Average per Balls in Play (BABIP) -- The percentage of balls in play (at bats minus strikeouts and home runs) that are base hits; research by Voros McCracken and others has established that this rate is largely random and has a norm of approximately 30%
Isolated Power -- The difference between slugging percentage and batting average; created by Branch Rickey and Allan Roth
Walk Rate -- Walks / (at bats + walks)
Whiff Rate -- Strikeouts / at bats

Stay in touch with the most passionate Fantasy staff in the business by following us on Twitter @CBSFantasyBB or Al Melchior at @almelccbs . You can also e-mail us at .

Data Analyst

Al Melchior has been playing Fantasy Baseball since 1994, getting his start in the Southern Maryland Anthropomorphic Baseball League (SMABL). He has been writing about Fantasy Baseball since 2000, getting... Full Bio

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