While we are just now reaching the quarter mark of the season, a sample that should still mostly be considered small, the following players have displayed a dramatic enough change in underlying skills that has increased or decreased their value significantly since being drafted back in March.
Jeff Samardzija – Samardzija entered 2012 with a career 5.30 BB/9 rate, but he's carried over a strong spring training into the season, as he currently sports a 3.00 ERA and a 1.16 WHIP with a 53:16 K:BB ratio over 51.0 innings. His 9.35 K/9 rate ranks 11th best in baseball, and among the 10 listed ahead of Samardzija, only one (Zack Greinke) has a better groundball|PERCENT|. His average fastball velocity of 94.8 mph ranks second best among all starters, so if his dramatic improvement in control is here to stay, Samardzija suddenly looks like a star. In fact, his SwStr|PERCENT|, which measures the percentage of total pitches a batter swings and misses with league average being 8.5|PERCENT|, is an MLB-high 13.3|PERCENT|. Samardzija looks more like a staff ace than a sell high in fantasy leagues.
Adam Dunn – After Dunn's OPS sat at .589 on April 17, there was obvious concern last year's disastrous season was the beginning of the end. Since then, it's become clear 2011 will go down as a huge outlier in an otherwise productive career, as he's back to his vintage self. Dunn has struck out in 40-of-42 games this season and is on pace to finish with 239 Ks, which would easily set a major league record, so it's safe to expect a batting average no better than his career .244 line. Still, Dunn's .349 ISO ranks third best in the majors, and in today's game when power is way down, home runs are that much more valuable. There's little doubt he's experienced some luck with a 31.8 HR/FB|PERCENT|, but his walk rate is up, his 0.48 GB/FB rate is a career low and his 23.5 LD|PERCENT| is a career high. If we held a draft today, Dunn would likely go more than 10 rounds higher than he did back in March.
Dee Gordon – After racking up 10 steals over the first 18 games of the season, Gordon has none over the past 11 contests, attempting just one over that span. Of course, it's tough to run when not on base, as Gordon's OBP currently sits at .244. That's accompanied by a .255 slugging percentage, as he's one of only four players in baseball with an OPS below .500. He's been utterly helpless against left-handers, producing a .152/.188/.174 line over 46 at-bats. For someone who has terrific speed with a 1.97 GB/FB rate and an 18.1 LD|PERCENT|, his .241 BABIP should certainly be considered unlucky, but it's worth noting his groundball numbers are skewed by 12 bunt attempts, and he hits far too many popups, possessing a 20.7 IFFB|PERCENT| that's fifth highest in all of baseball. Gordon's bat simply doesn't look ready for major league pitching. I predicted he'd lead MLB in stolen bases before the season started, but at this point, there's a better chance he spends a long stint back in the minors than that happening.
Clay Buchholz – After Buchholz broke out with a 2.33 ERA in 2010, there were calls for regression since that came with a poor 120:67 K:BB ratio over 173.2 innings. While some of that correction occurred in 2011, he still posted a solid 3.48 ERA before going down to injury despite another K:BB rate that was under 2.0. With consistently strong groundball rates, it was entirely possible Buchholz was a pitcher who could prevent runs better than his peripherals would suggest, and with a good pedigree at age 27, there was also a real chance he'd make a leap. After all, Buchholz's minor league numbers were dominant (2.44 ERA, 10.2 K/9, 2.5 BB/9 over 447.0 innings), and he should receive a lot of run support pitching for Boston. But Buchholz has only gotten worse in 2012, with an ugly combo of 5.11 K/9 and 4.70 BB/9 rates. He's certainly not as bad as his current 7.77 ERA, and things will get better, but Buchholz's 5.23 xFIP is the second worst among all starters in baseball, so it's safe to say he's unlikely to live up to his once high expectations. In fact, he may not even be rosterable outside of AL-only leagues.