Baseball is often full of surprises.That big run producing bat a team was relying on before theseason started can get hurt or underperform, but then a hitter can come out ofnowhere to surprise and help pick up the slack.The same can happen on the pitching front with an armconsidered merely as a depth starting option at the outset of spring training.When given a chance, that arm can make the most of an opportunity when they arethrust into a more prominent role because of injuries or poor performance fromother starters.That is exactly what right-handed pitcher Corey Kluber hasdone this season. When the Indians began spring training in Arizona back inFebruary, he was the eighth starter in the organizations pecking order, butwith his performance to date he now is arguably their first or second beststarter.Kluber, 27, found his way into the Indians starting rotationin late April because of a unique set of circumstances. Right-hander BrettMyers came up lame and went on the disabled list, and right-hander CarlosCarrasco was unavailable because he had an eight game suspension hanging overhis head. The Indians also wanted to keep young phenom right-hander TrevorBauer in Triple-A Columbus to get consistent work.So Kluber got a chance to move into the rotation in what wasfirst considered a temporary move. He made his first start on April 28th inKansas City and had a remarkable outing going seven strong innings allowingjust two runs on seven hits, no walks, and had six strikeouts.That first start in Kansas City set the stage for Klubersnext nine starts. He has since settled into the rotation nicely, compiling a5-4 record with a 3.58 ERA. He is giving up a hit an inning though is alsoaveraging a strikeout an inning, and most incredibly is averaging over fivestrikeouts for every walk he allows.Over his 12 total appearances he really has had just one poor outing,which was the one on May 10th at Detroit when he allowed eight runs on 11 hitsin 4.2 innings.So what has led to Klubers surprise showing this season?And is it sustainable?Time will tell, and remember, Carlos Carrasco had a similarstretch of good performance in June of 2011. To make a believer out of amajority of people Kluber will need to maintain these consistent outings overthe rest of the season. In fact, he hasalready made a believer out of a lot of people, including yours truly, who hasnever been firmly on the Kluber bandwagon before this season.If you have not yet jumped on the Kluber bandwagon, it mightbe time to get on.Kluber is proving to be a workhorse starting pitcher thatcan haul innings, maintains his composure in the toughest of situations, andhas extraordinary stuff. Since acquiring him in July of 2010 in a trade forJake Westbrook, the Indians have always been very high on his stuff and havemaintained a belief that it is the best in their system.Kluber is proving himself with a good two-seam fastball that sits at 90-94MPH and has touched 96 MPH. The fastball has top notch movement which makes ithard for hitters to square it up, and he has three good secondary offeringswith a plus slider, changeup and cutter that he can attack hitters with.His slider has a good, hard break that has beendevastating on hitters this season who he gets to swing and miss.The cutter he added late in 2011 is also proving to be an effective majorleague offering as well.What is most impressive about Kluber is how he commands the zone so well, but also has swing and miss stuff. That is a rare combination as strikeoutpitchers will often walk their fair share of hitters and command-control guystypically pitch to contact and get few strikes swinging.What has come along so well this season with Kluber is his fastballcommand, which was something that gave him some trouble the prior two seasonsand led to inconsistency with his performance.Because of the fastball command issues of the past he had troublefinding his rhythm, throwing consistent strikes, and keeping the ball down inthe zone, which in turn led to him pitching from behind way too much. Hesovercome that limitation, and his performance has spiked as a result.Armed with a sinkingfastball with more velocity and movement than in years past, a slider whichwent from very good to top shelf, two other solid secondary offerings, and goodcommand to boot, you have a pitcher putting forth a breakthrough performancethis season.At this point,Kluber can remove the interim label from his spot in the starting rotationbecause he has earned a more permanent spot in it and may have solidifiedhimself as a foundational piece to the Indians rotation for the next severalyears.