TwinsCentric: Is Samuel Deduno a lock for the 2013 rotation?

The front office will likely do some shopping-n-swapping to infill the rotation this winter however one member of the Twins staff who is almost certain to get an opportunity to win a role next spring is Samuel Deduno.

For the most part, Deduno's unexpected and head-scratching success has continued across his 13 starts. He has struggled to get ahead of hitters (54% first pitch strike rate compared to the 60% league average) and then falls deeper behind in the count (8% of all his plate appearances went to 3-0 counts) and ultimately loses the battle of the balls. As such, his 15% walk rate is the highest in baseball among all starters with a minimum of 70 innings pitched. Because of this, the expected Fielding Independent Pitching metric -- which takes batted ball trajectory, strikeouts and, most pertinent to Deduno, walks -- calculates him to have an earned run average closer to 4.60 rather than the 3.84 that he is currently sporting.

If you were applying the standard statistical analysis to this situation, it would be easy to label the right-hander as a case ripe for regression. After all, Deduno has allowed 48 hitters on base via walk but somehow has managed to keep a high percentage of those from scoring. He has stranded nearly 80% of all base-runners which is well above the league norm of 72%. At some point, a ball chops through the infield here or a subsequent hitter manages to get one up into the jet stream to plate some runs there. Yet again, Deduno has been extremely fortunate in that respect as well.

Consider this for luck: Line drives become hits approximately 73% of the time. It makes sense when you think about the trajectory and speed that causes frozen ropes to be quite hard to defend. Yet line drives from Deduno's opponents have turned into hits just 60% of the time. Somewhere down the line, that number is surely going to regress to the mean and drive his overall batting average on balls in play – which is at a miniscule .258 right now – back closer to the league average.

While regression in 2013 would be the anticipated response based upon the above two paragraphs, if you consider how little opponents have been able to actually square up on his repertoire, there could be a correlation as to why the majority of his balls put into play have been fielded.

The biggest factor is his ground ball rate. At 58%, his worm-killing rate is the seventh highest among those with a minimum o f 70 innings. The next significant indicator of his ability to avoid heavy contact is his 18% infield fly ball rate. What that means is that nearly 20% of all the fly balls hit are not getting past the infield dirt. As of Thursday, only former Twin Johan Santana (19%) has been able to keep a higher percentage of flies from leaving the infield. What this statistic is indicative of is their ability to get hitters to lunge and make off-balanced contact with pitches.

When first introduced to the Twins, the initial reaction was that Deduno came equipped with a fairly legit curveball. In 2007, Baseball America graded his curve a 70 on the scout's 20-to-80 scale. In 2010 Deduno was pitching in the Rockies organization. Coming off one spring training outing as a 26-year-old manager Jim Tracy simply said "Those were paralyzing-type curveballs." Major league hitters would likely agree with those assessments of the pitch as they have hit just .153 off of it and he has racked up 39 of his 54 strikeouts with the curve.

As impressive as his curve ball has been, Deduno possesses a ridiculously underappreciated weapon in his fastball.

According to Baseball Prospectus's Pitch F/X leaderboard, Deduno's four-seam fastball has induced the highest amount of ground balls on that pitch since the inception of Pitch F/X in 2007. Sure, it is only 403 pitches but his 68% ground ball rate on a four-seam fastball is downright unbelievable.

The reason he is getting such an incredible amount of grounders is because of the sink action he has on his "crazy fastball."

Deduno's movement on his four-seam fastball almost defies physics as four-seamers – which because of the backspin created more often tend to give the illusion of "rising" - generally have the least amount of sink among all pitches. On average, Pitch F/X says that the majority of four-seam fastballs have a vertical movement of roughly 8.60 in measured in 2009. As a rule of thumb, the higher that number, the greater the "rise" action or conversely, the lower that number, the greater the sink. To provide some perspective, the Angels' Jared Weaver, whose fastball has been described as having "hop", has a vertical movement of 12.23 on his fastball. On the other end of the spectrum, the Indians' Justin Masterson, who has one of the "heavier" fastballs, has a vertical movement of 4.24. That use to be the most sink on a four-seam fastball. That is, it was until July 7 when Samuel Deduno started pitching. Deduno's four-seam fastball has a vertical movement of 2.76.

For those who are not properly geeked up by those numbers, here's another visual: The average split-finger fastball has a vertical movement of 3.37 which means Deduno's four-seam fastball has more vertical sink than an average split-finger fastball.

Take a look at the pitch's action in all its .gif glory:

This particular one not only sinks, but has arm side run for days as both Seattle's Trayvon Robinson and Ryan Doumit were fooled by the late movement.

Later, Doumit was at a loss in attempting to explain the movement and where it comes from. "I don't know if it's finger pressure or wrist angle or what it is, but he's got a gift of natural movement on the fastball and the changeup," said the Twins catcher.

Deduno's movement is exciting and provides explanation as to why he is out-performing his Fielding Independent Pitching figures. Hitters simply cannot square up on anything they swing at. However, if they put on a swing boycott, his inconsistent control may lead to too many free passes – beyond the point where he can continue to strand them all. This was evident in his most recent start against the White Sox where he walked five and three of those came around to score.

Deduno will take the mound tonight to take on the Tigers. Watch for some of that crazy fastball movement and if he can locate it in the strike zone.