In this article…
After pitching seven scoreless innings against the Toronto Blue Jays and lowering his ERA to a league-leading 1.01, Boston pitcher Clay Buchholz was accused of cheating by Blue Jay analysts (and former pitchers) Dick Hayhurst and Jack Morris. Both pitchers noted that they saw a glistening substance on Buchholz's forearm that he kept touching throughout the course of the game. Buchholz and Red Sox manager John Farrell have both denied anything, saying that he is only using Rosin (which is legal).
SI's Tom Verducci closely examined video of Buchholz and came away with these observations:
Buchholz's left forearm glistens this year with some kind of substance that is not rosin or perspiration. As the righthander admitted, he does keep water on his uniform and in his hair and does pat the rosin bag on his left forearm — all apparently legal. But rosin is white and has a matte finish. Something wet and mostly clear glistens from Buchholz's left wrist to his elbow, the moisture of which darkens the edge of his left undershirt sleeve…
He regularly rakes his right index and middle fingers across his left forearm, being careful to keep his other fingers raised…
The case of Buchholz in Toronto became uncommon for several reasons: he was called out by former pitchers, the lack of discretion in the extent of coverage of whatever is on his left forearm and the fact that in the year after he posted a 4.56 ERA without a stain on his sleeve he has an MLB-best 1.01 ERA and is throwing the baseball better than anybody in the major leagues.
It should also be said that Verducci notes in his article that most pitchers will try to gain some form of advantage by improving their grip, which is exactly what Buchholz is being accused of. When you can improve the grip, you can put more spin on pitches and throw them with greater velocity. Verducci noted that Buchholz's two-seam fastball is markedly improved this season and is a big reason for his overall improved performance.
With two sides firmly planted, this is obviously a case that needs further investigation. I had attributed Buchholz's fast start to the return of Farrell, who was his pitching coach when he first came up. This accusation obviously speculates other possibile things to attribute Buchholz's success to. This will get worked out one way or another, but MLB certainly needs to look into this a little more.