University of Missouri ace Max Scherzer was Arizona's first round pick in 2006, 11th overall. He pulled the "go to indy ball and sign late" stunt pioneered by Scott Boras, though he eventually signed before re-entering the draft pool.
Scherzer began 2007 with independent Forth Worth, posting a 25/4 K/BB in 16 innings with a 0.56 ERA. After signing with Arizona, he went to Visalia in the Cal League and posted a 0.53 ERA with a 30/2 K/BB in 17 innings. Very similar numbers which imply that the independent American Association is approximately equivalent to A-ball in competition. Scherzer moved up to Double-A after the Visalia tuneup, but struggled at times, with a 3.91 ERA and a 76/40 K/BB in 74 innings: good strikeout rate, but too many walks. His velocity was also down at Mobile, just 88-93 MPH. He was back up to 93-98 in the Arizona Fall League, used in relief. I gave him a Grade B+ in the book this year.
Scherzer has been a monster this year. Through four starts for Triple-A Tucson, he has a 1.17 ERA and a superb 38/3 K/BB ratio in 23 innings. He's holding hitters to a .146 average. The Diamondbacks promoted him to the major league roster yesterday. Current word is that he will be pitching relief, but an opportunity to start soon could arise, particularly if Micah Owing's ankle is still bugging him later this week.
What can we expect from Scherzer? When everything is right with him, he features a blistering fastball that sinks. His slider is also very strong, and his command has been terrific this year. There's still some question about his changeup, and it remains to be seen if Scherzer will fit best as a starter or reliever in the long run.
Scherzer's statistical track record isn't long enough to draw any massively broad conclusions based on the numbers, other than saying his K/IP confirms his dominance. Scout-wise, here is some video for you to look at:
Max Scherzer of the Visalia Oaks ( Single-A Arizona ) (via farmsystem)
The low 3/4 arm slot looks like it add some deception, but I've heard some scouts say that his delivery has effort in it and his durability may not hold up in the long run. Personally, given what he did in Triple-A this year (admittedly a very small sample,) I wouldn't want to give up on him as a starter in the long run. I'd use him as a long reliever/spot starter this year if I were the Diamondbacks, then ease him into the rotation full-time next season. If he fails at that, then move to the pen.