Buchholz's cutter 2 pitches in 1

CHICAGO -- One potential obstacle to Clay Buchholz's remaining undefeated when he takes the mound Wednesday was removed when the White Sox announced that ace left-hander Chris Sale has been scratched because of what the team called a mild case of tendinitis.

Instead of facing Sale, Buchholz (6-0) is scheduled to oppose left-hander Hector Santiago, who didn't make it out of the fourth inning against the Angels in his last start.

One of the keys to Buchholz's success this season has been the effectiveness of his cutter, demonstrated here by numbers provided by Michael Bonzagni of ESPN Stats & Information.

In his last start Saturday night, in which he allowed two runs in seven innings in Minnesota and was not involved in the decision, Buchholz threw his cutter 21 times. Twins hitters went 0-for-3 with a strikeout and a walk in at-bats ending with the cutter.

Bonzagni compared Buchholz's cutter this season with last and noted a drop in average velocity of 1.5 miles per hour, from 89.3 to 87.8 mph. The drop in velocity, however, was accompanied by a significant change in the pitch's horizontal movement, from 1.8 inches last season to 3.4 inches this season. That change has resulted in a huge difference in opposing hitters' slash lines against the pitch. Last season, they batted .248 with a slugging percentage of .323. This season, it's a .135 average, with a .154 slugging percentage. The strikeout percentage on the pitch also has risen, from 13.8 percent last season to 17.2.

I presented Bonzagni's numbers to Buchholz, and he acknowledged that he is basically throwing two different cutters this season. “I throw one that's a get-me-over pitch that I throw a little harder," he said, “and the other is more of a put-away pitch, which I take something off. It's almost like having two different pitches. It's a matter of changing the grip and how much pressure I apply to the ball with my fingertips."

According to Inside Edge, Buchholz has allowed only two well-hit balls in 52 at-bats ending with his cutter (.038 well-hit average). Last season, he allowed 25 well-hit balls in 133 at-bats ending with his cutter (.188 well-hit average).

“I think it's more feel on Clay's part," manager John Farrell said. “When you reduce the velocity, you're probably going to increase the break. Those go hand in hand. So, this is more about Clay getting a better feel for his pitch mix and what he's determined to be most effective in the four-pitch mix that provides more definition in keeping his fastball and cutter from blending into each other.

"I think the swing and miss and reaction of the hitters tells you more than anything. And it's clear that he's got very good stuff."