Bryan Woo Sucked in College. Now He’s a Star in MLB | Baseball Bits

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That's code 50FOOLISH at factor75.com to get 50% off plus free shipping on your first box. Here's a healthy dose of perspective. At the end of the day, pitching is all about run prevention, which is why it's so bizarre that this video is about a pitcher who, in his draft year of 2021, was the 73rd best pitcher in his college conference by ERA. Brian Wu's final collegiate season for the Cal Poly Mustangs of the Big West Conference ended unceremoniously as he underwent Tommy John surgery in April, but the draft was coming up that summer, and Mariners Director of Pitching Strategy Trent Blank was all aboard the Brian Wu train. Although he was the number 337 ranked draft prospect according to Baseball America, the Mariners drafted him 174th overall in the 6th round. Why the reach? As Blank put it to GM Jerry DiPoto, I know this is gonna sound crazy, but this guy would be 1-1 for me. If Blank had his way, Wu wouldn't have been a 6th rounder, rather, the number one overall pick in the entire draft. He was that confident in a reliever with a career college ERA well over 6 who just had major elbow surgery. And he was right. 3 years after the draft and 2 years after recovery, Wu was a top 10 starter in the big leagues by ERA. What did Trent Blank and the Mariners see in Brian Wu that nobody else could? And how did they see a great MLB starter hiding underneath a bad college reliever? The boring answer to that question would be his strikeout rate and walk rate. Despite the poor ERA, Wu had the best strikeout percentage minus walk percentage in the Big West Conference that year, a simple metric with a stronger correlation to future ERA than past ERA alone. But of course, every big league team knows that already. Wu had the second highest draft year ERA out of the 19 college pitchers selected in the 6th round in 2021. And contrary to expectation, the higher ERA hurlers from that round have tended to reach the big leagues more so than the effective run preventers. Scouting departments are able to use advanced data to divorce good process from bad results. At Cal Poly, it started with a track man in their ballpark by 2020. These systems, like Hawkeye's statcast at the big league level, use high-speed cameras and radar to track the baseball in flight. For pitchers, that includes measurements like velocity and movement. But even Wu's fastball wouldn't have jumped off the page in that regard. In the majors, he's averaged about 15 inches of induced vertical break, meaning it rises 15 inches higher than a theoretical pitch thrown at the same velocity, but without any spin. The ball doesn't actually rise, but it uses that imparted spin to fight off gravity the best it can. This quality is commonly referred to as ride, or carry. At 15 inches of break, Wu is actually below the league average four-seam fastball. As described in his draft scouting report, his velocity was mid-90s out of the bullpen and low 90s those rare occasions he actually did start. For the sake of comparison, the only 2021 6th rounder with the worst ERA, Carson Seymour, was routinely pumping upper 90s as a starter. Nowadays, Wu averages 95 mph on his 4-seam and 2-seam throughout his starts, a major uptick that Trent Blank and the Mariners might have been able to project based on video. Wu's athletic delivery features excellent hip-shoulder separation, a hallmark of fireballers throughout the years. As the front leg swings open, pointing the hip towards the plate, the shoulders and chest remain closed, pointed towards the dugout. Eventually, they too uncork, creating a body-wide rubber band effect. A prospect with mediocre velocity but elite hip-shoulder separation flashes the potential to throw harder someday. But Brian Wu's standout quality wasn't how hard he was throwing, and it wasn't how the ball moved either. What mattered was where exactly that pitch was coming from. Brian Wu releases the baseball approximately 5 feet off the ground, 10 inches lower than the MLB average. Pitchers don't throw from wonky arm angles just for fun, they do it to create difficult angles for hitters. Pitchers are tall people who stand on a hill. The average pitcher is 6'3", throwing from a 10-inch high mound, and typically releasing the ball at or above head level. They're aiming for a strike zone, the middle of which is only 2.5 feet off the ground. That means the average pitch loses about 3.5 feet of elevation during flight. It starts high and ends low, creating an angle specifically called the Vertical Approach Angle, VAA for short. In order to mirror the ball's downward trajectory and maximize contact, hitters need to swing with an upward trajectory, rather than flat. Here's Ted Williams. For a more modern example, some of the best pure hitters of today swing with more exaggerated uppercuts than most. Luis Arias is a prominent example, with three batting titles to his name and counting. The same could be said about career .300 hitter Freddie Freeman. But with batters swinging up to increase the potential area for contact, pitchers can create a flatter approach angle to decrease that area. The two things they can do are release the ball lower to the ground, and aim it higher in the zone. With a vertical approach angle of negative 3.8 degrees, Wu's foreseam creates the flattest angle of any foreseam fastball thrown at least a thousand times since 2023. His flatter approach angle causes him to miss bats despite fastball movement and velocity that, in a vacuum, wouldn't otherwise stand out as elite. In the pitching world, weird often equals good. One of the worst things a pitcher can be is too cookie cutter, and a flat approach angle is Wu's version of quantifiable funk. No doubt, when the Mariners were looking over Brian Wu's pitch tracking data, they were enamored with his potential to create unorthodox angles. His arm slot dropped throughout his college career, and that drop continued as he turned pro and recovered from elbow surgery. The lesson here is simple. Everything a pitch does is relative to the release point and arm angle. The pitches with the most vertical break tend to be over-the-top deliveries with high release points, like a Justin Verlander foreseamer or Tyler Glasnow curveball. They need to get on top of the baseball to apply that backspin or topspin. Pitches with the most horizontal break often come from lower slot deliveries, like a Christopher Sanchez two-seam or Chris Sale slider. Creating a disconnect between the arm angle and pitch movement is a form of deception. Clay Holmes is over-the-top, but throws a sinker with very little vertical movement, aka ride, but plenty of horizontal movement, aka run. Tanner Scott's fastball delivery, meanwhile, creates surprising ride from a three-quarters arm slot. Brian Wu's arm slot is somewhere between three-quarters and sidearm, in comparison to a true sidearmer like his teammate Luis Castillo, yet despite a 12-degree difference in arm angle, they still release from the same height. This is because Wu glides down the mound and dips his shoulder and elbow more to get on top of the baseball, giving his fastball more ride, while Castillo's has more run. Wu's induced vertical break is relative to his delivery. Among all Big League four-seamers, his is only 35th percentile in carry, but 84th percentile among pitchers with a similar release height, and 77th percentile among pitchers with a similar arm angle. Suddenly, his below-average pitch movement is above-average, with proper context. Taking into account that plus his VAA and velocity, you can see what Trent Blank and the Mariners saw hiding behind his unimpressive college ERA. Wu also throws a seam-shifted wake-sinker to complement his four-seamer. He throws both pitches with the same velocity, averaging 95, but the two-seam trades off 8 inches of induced vertical break for an additional 8 inches of arm-side horizontal break. Perhaps what's most impressive is how consistent he is with his arm angle and release point when throwing these two fastballs. Some four-seam and two-seam throwers have to vary their arm angle to get the desired effect. Seth Lugo, thrower of many pitches, is releasing his four-seamer up here, and his two-seamer over there. But Wu doesn't cheat at all, identical arm angle and release points for both. The Mariners would have also observed Wu's rapid improvement in strike throwing, a trend that has continued since going pro. His walk rate fell precipitously throughout his career at Cal Poly, and in 2024, at the Big League level, he put together the sixth lowest walk rate of the last decade among pitchers with at least 100 innings. He also had the highest percentage of pitches in the strike zone, according to StatCast. These numbers demonstrate control, but what about command? Not all strikes are created equal. So let's make our own, quick and dirty, adjusted zone percentage. Middle-middle doesn't count, that's too dangerous, but the edges of the strike zone should count as double. This rewards pitchers for throwing strikes that are difficult to hit. In our adjusted version of zone percentage, the gap between 1st place Brian Wu and 2nd place Joe Ryan is greater than the gap between Ryan and 24th place Dane Dunning. In 2024 in particular, he was just daring batters to hit his fastballs, and they didn't. If he were throwing fastballs with bad qualities, he'd be getting crushed, but Wu has one of the highest swinging strike rates on his foreseam among starters the last two seasons. The sinker, meanwhile, is a soft contact generator, one of the lowest average exit velocities in the same time frame. Wu's secondaries are still a work in progress. He added 3 inches of armside fade on his changeup between 2023 and 2024, which helped win facing lefties, yet it might not have the velocity or movement to differentiate itself from the sinker. Left-handed hitters crushed him in his rookie year of 2023, but he dominated both sides of the platoon during his second big league season. The sweeper in particular has blossomed against righties. The fastballs are still very much his go-to pitches in most circumstances. The Mariners have tended to target pitchers with great fastball qualities first and foremost. That's Logan Gilbert's velocity and extension, that's Bryce Miller's induced vertical break, that's Luis Castillo's arm angle and release point, and that's George Kirby's pinpoint strike throwing. Brian Wu is a special combination of all four. No wonder Trent Blank wanted him first overall. After his Tommy John surgery in April of 2021, Wu has ascended from injured struggling college reliever to 6th round pick to one of the more promising young starters in Major League Baseball. During his career at Cal Poly, he overlapped with 6 other big league pitchers in the big west, with more likely to come. Of those 6, Wu was by far the worst in terms of run prevention. The college reliever to MLB starter path is also unorthodox. In Wu's short big league career, 59 college draftees have served as starting rotation fixtures around the league, and only 6 of them weren't regularly starting during their draft year. That pipeline tends to only work in reverse, college and minor league starters who shift to the bullpen. Like most promising pitchers, the only thing that can derail Brian Wu now is his arm health. He's already had Tommy John once, and has a checkered injury history in the majors already. He missed time in his 2023 debut season with forearm inflammation, was shut down in spring training 2024 with elbow inflammation, left his first start of 2024 early for precautionary reasons, was scratched from a start in June and had an MRI, while also missing time in the second half with hamstring issues. But the simple fact of the matter is, he's already outperformed his draft slot by magnitudes. He went 174th overall, but has generated the 10th best war of the class to date, and that's with missing a pro year recovering from surgery. If there was a 2021 class redraft in 2025, maybe he wouldn't go first overall like Trent Blank said, but he'd go pretty darn high, certainly well ahead of the actual first overall pick, Pirates catcher Henry Davis, as well as the second overall pick and first pitcher off the board, Rangers righty Jack Leiter. So whether he fully blossoms into a Cy Young candidate or not, Brian Wu's success is a win for the Mariners and a win for Data in baseball. Hey you, thanks for watching.