So maybe he doesn't have a solid nickname yet, but Odisrighthere Dismine has given up just 4 earned runs through his first 4 big league starts. That will turn heads just as quickly as any play on words. Before the season Odie was described as a "bubble guy" with average stuff across the board - not unlike the dozens of rotation swingmen and sometime major leaguers that continuously ride the shuttle to AAA. Josh Byrnes (peace be upon him) saw a bit more potential in him - describing the right-hander as an "old generation Cuban pitcher" akin to Livan Hernandez or El Duque.
There is some precedent for success for deceptive pitchers lacking premium stuff. You almost have to invoke the "crafty lefthander" trope despite Despaigne's handedness. In order for a prototypical "junkballer" to succeed, he's got to keep hitters guessing rather than sitting on specific pitches or hitting zones. In the absence of a true "out" pitch, Despaigne throws several different pitches with relatively similar frequency, showing little preference for any specific pitch in specific circumstances. Depending on what type of pitch-tracking system you use Despaigne throws a roughly equal number of fastballs, sinkers, sliders, cutters, changeups, curveballs and pitches you'd have to classify as ¯\_(ツ)_/¯. Additionally, the Cuban national employs one of several distinctive armslots to effectively hide the ball from hitters and alter the trajectory and movement of the pitch. Notice specifically that he will drop the arm slot against righties to give his pitches more horizontal movement so that the pitch tails away from hitters:
This unpredictability and movement makes it difficult for hitters to key-in on payoff pitches and connect with the meaty part of the bat. Catching hitters off balance doesn't necessarily lead to a lot of strikeouts in the absence of premium movement or velocity - even when a pitcher like Eric Stults is firing on all cylinders you aren't going to see a ton of whiffs. Despite Despaigne's impressive minor league strikeout numbers (in ~30 IP) it is important to note that he hasn't shown the ability to consistently rack up Ks in the Cuban league or in the MLB. For Despaigne "fooling" hitters is going to have to lead to weak contact in the form of popups and grounders.
Beyond the numbers, one of the most impressive aspects of Despaigne's short MLB tenure has been his ability to walk the proverbial tightrope and casually escape from jams when the opponent has men on base. At first glance his 89% strand rate seems prime for regression back to the ~70-75% you expect to see from Padre pitchers. However, like BABiP or HR/FB ratio, it is important to look for indicators that might impede simple regression to the mean. Just as speedy ground-ball hitters routinely outperform the average BABiP, it is possible that Despaigne possesses a skillset that predisposes him to a better-than-average strand rate. Without trailing too far into sports-punditry tropes - some guys just have another gear that they can shift into during big situations. Guys like Justin Verlander are great at dialing in a little extra heat on their fastballs when opponents threaten. While Despaigne isn't going to blow any hitters away with gas, his deep bag of tricks and above-average ground ball rate work in his favor with runners on base. Double plays are just about the most efficient rally killer this side of Will Venable.
There are two big rules to being a junkballer: 1. Limit free passes. 2. Keep the ball in the yard. When looking to Byrnes' Cuban comparable pitchers it is clear that Livan and Orlando Hernandez each had their least effective seasons whenever their walk or home run rates crept upwards. As a Padre, Despaigne will surely benefit from the team's superb coaching staff and cavernous home ballpark. Petco park itself is a doubly valuable asset for pitchers in that it limits home runs by nature, but this factor also allows for pitchers to approach batters more aggressively, thus limiting walks. Its like how you can try to pull off intense facial hair when you have a really good haircut.
"First round talent, with question marks" is basically prospect speak for "Hot, but won't stop talking about how meaningful her tattoos are." These types of pieces are hot targets in trades and at last call because people have different evaluations and assessments of payoff versus tolerable downside. Despite his imposing 6'5" frame, Hahn has always been a durability concern and has already survived one Tommy John surgery. Despite the physical trauma, Hahn still relies heavily on his hammer-curveball which serves as the perfect compliment to his low-90s sinking fastball. In a perfect foil to Despaigne, Hahn relies heavily on his two bread-and-butter pitches and will only occasionally mix in his changeup.
"Doesn't have a third pitch" is a common knock on promising pitching prospects. Recently, you could argue that this was the cause of death for Padres prospects like Anthony Bass, Simon Castro and others. These guys could look very good for short stretches only to have hitters "figure them out" with repeated attempts. Every so often though there is a Tyson Ross-type who's primary pitches are so good that they make up for the lack of variety. AJ Burnett provides an interesting template of sinker/curveball-dominant pitchers in recent years - he streamlined his repertoire to great success once his fastball started to lose some zip.
Hahn's stuff is the real deal. The curveball that he leans on so heavily is rated at +2.65 runs above average per 100 pitches which ranks among the very best pitches in the game, and clearly one of the most devastating breaking balls. The nature of pitch values are such that they are only generate data points on pitches that end at-bats, indicating that Hahn's curve is functioning like a true "out-pitch." More than this we can also look to Hahn's elite swinging strike rate (11.4%) and healthy ground ball ratio (50%). Through seven starts, sample size bias is of course a concern, but these secondary stats are the type that stabilize more quickly than FIP or BAA - it's very difficult to make major league hitters swing and miss in the absence of swing-and-miss stuff.
Effective pitches are of course only part of what makes an effective pitcher. The big obstacles between Hahn and true stud-prospect status have always been durability and control. The 79 innings Hahn has thrown this season are already the most he's ever thrown in a calendar year, even dating back to college. For a guy with a surgically repaired elbow and heavy reliance on an elbow-shredding out-pitch, the club must be eternally vigilant with Hahn's workload. When looking at Hahn's frame and devastating sinker/curveball tandem it is impossible not to consider Casey Kelly, who threw dozens of curveballs in his final start before blowing out his elbow in 2012. Those who remember Kelly are already closing their eyes and inhaling deeply. Kelly's elbow is still recovering from the trauma and it is unclear if he will ever recapture what made him such an exciting prospect leading up to his debut. Thus far the team has been quite strict with respect to Hahn's pitch counts and will probably build his arm strength slowly with hopes of acclimating him to a true starter's workload by 2016 in the best case scenario.
The ugliest aspect of Hahn's game thus far is his 3.54 bb/9 walk rate, which would rank among the league's worst qualified starters. There are good pitchers who walk more hitters than Jesse Hahn, but not many. His propensity to rack up strikeouts and generate ground balls helps to limit the home run ball and keep him from hemorrhaging runs from free passes. Still, Hahn will have to improve his walk rate before his insane .185 opponent average returns to earth. Looking back to the Anthony Bass example - despite a streak of excellence to start his Padre career, Bass never developed a third pitch to compliment his fastball and breaking ball, and he never was able to reign in his wildness. The baseball gods eventually caught up with Bass and his ERA is currently sitting near 6.00 for the Houston Astros. Bass wasn't quite on Hahn's level in terms of talent, but there have been plenty of young starters with potential that have paralleled his career trajectory.
Further proving that Hahn is Despaigne's perfect foil - Hahn could stand to show a little more calm under pressure. Hahn looks considerably less comfortable pitching from the stretch, and appears to get rattled after he gives up hits. With starters that rely heavily on movement and breaking pitches, there has to be an understanding that the ball isn't always going to move the way you want every time out. There are going to be days when he doesn't have his best stuff and Hahn is going to have to learn to pitch around that. At this point it shouldn't be a huge cause for concern since the former Hokie is a rookie with fewer than 50 professional starts under his belt. It is however one of the "intangibles" that good pitchers develop and bad pitchers often don't.