One of the biggest surprises of the Twins season has to be the performance of starter Scott Diamond. Written off by many as just another “soft tossing pitcher” in the organization, Diamond has shown mastery of the strike zone and has been getting ground outs by the barrelful. This has led to a 10-5 record and a 2.91 ERA – the sixth best in the American League.

While radar gun enthusiasts and strike out fanatics are not likely thrilled by his skill set, Diamond is proving that it is not necessary velocity that makes the pitcher. Let’s take a look at what has made him so successful this year.

(1) Release Point/Plane Change

Diamond’s over-the-top release point gives him a very high angle. Pitch F/X, which captures the first data of a pitcher’s pitch at 55 feet, shows that Diamond’s pitches are at approximately six-feet-four inches on average – which, by comparison, is slightly higher than the taller lefty teammate Tyler Robertson. Combine that with crossing the plate at the knees or lower regularly and you have a solid recipe for grounders.

As 1500ESPN.com’s Phil Mackey pointed out recently in a great piece detailing Diamond’s outstanding game preparation, the majority of his misses are low. Mackey cites a stat that said just 6% of his entire offerings this season have missed the strike zone high. This downward trajectory ensures that he is changing planes and making it more difficult for hitters to do anything besides hit the top of the ball thereby inducing a high percentage of ground balls.

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There’s more than just his ability to keep the ball down in the zone that has made him effective this year. His curveball, which may be his best pitch, may be the key behind elevating his fastball from pedestrian to impressive.

(2) Noon-to-Six Curveball/Effective Velocity

His curve is released at the same point as his fastball but, unlike other pitchers’ sweeping version, Diamond throws his with a 12-to-6 break (north-south movement versus the east-west type). Because the path of his curveball follows the same trajectory as his fastball before it dips – as opposed to many 11-to-4 curves which deviate off of the fastball’s path sooner - hitters will have a more difficult time deciphering between the two offerings. This is what has been one of the practices of the “Effective Velocity” teachings.

Part of the Effective Velocity theory is that hitters have approximately 20 feet to decide what the pitch is as they are beginning their swing. The longer an off-speed pitch looks like a fastball or vice versa, the better the odds are the hitter would be fooled by the pitch. Because Diamond’s fastball and curveball share roughly the same plane for the first 20 feet, opponents are having troubles identifying which is which before it is too late.

From his Pitch F/X chart you can see how the fastball (blue circles and red triangles) and the curveball (green squares) have little horizontal movement yet the curveball will have a quick drop:

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Roughly eight miles an hour and several inches of drop separate the two pitches but the two complement each other well. And Diamond continually teases opponents with this breaking pitching which likely keeps opponents off of his fastball. By throwing his curve 30% of the time – the third highest rate among qualified starters – he likely disguises his 89 mile-per-hour fastball effectively.

(3) Battler

He also possesses a bulldog-like determination on the mound of not giving in to hitters. For starters, he rarely issues free passes or puts himself in drastically bad count situations. Baseball-Reference.com says he has only had 10 3-and-0 counts – the fewest among starters with 100 innings or more. When he does fall behind hitters he is able to navigate out of trouble. While most pitchers are cuffed around when they are behind in the count, according to his “Batters Ahead” split opponents are holding just a 760 OPS. That is more than 200 points better than the league average of 974.

Will Diamond remain a winning pitcher? If he continues to have stellar defense and posts a 3.69 expected fielding independent number (xFIP) next year, there is certainly a chance he’ll put up very good stats and win a high portion of his games. Based on his repertoire, consistent peppering of the strike zone and studious nature of the game, there is little reason to think he cannot repeat next season with a similar xFIP.

Still, on the flipside, his offense in 2012 has been extremely generous to him. In fact, his 7.40 runs of support per nine innings is the second highest amount of support among qualified starters. If that figure starts to slip in 2013 -- which it is almost certain to do – Diamond is surely due to come up with the short end of the stick. Even great pitchers are unable to manufacture wins without the aid of their hitters – after all, Bert Blyleven can tell you all about losing ball games 2 to 1 or 3 to 2.