Wilfredo Boscan. Last season, as an 18-year-old Venezuelan pitching in the United States for the first time, Wilfredo Boscan was among the youngest pitchers in the Northwest League, regularly facing players 2-4 years his superior.

Not only was he one of the youngest pitchers in the league, he was also one of the best pitchers. Boscan went 9-1 and averaged just over one strikeout per inning while maintaining a 6.36 K/BB ratio. On top of that, Boscan has been lauded by several people for his ground ball rate in each of the past two seasons.

Boscan took the mound on March 19, 2009 in a Low A spring training game on the back fields at the Rangers complex. The following video was shot at 210 frames per second.

Boscan has very smooth mechanics, but he has a few inefficiencies and a pretty noticeable reverse forearm bounce. Boscan starts his delivery with his shoulders lined up outside the right-handed batters box, and he brings the ball behind his back before striding closed. Instead of using his hips to drive around his closed front leg, he drives his pitching shoulder over the top of his front leg. This is good when it eliminates forearm flyout, but in Boscan's case, it does not.

Boscan appears to pronate on his fastball, but it is hard to tell for sure at 210 fps. He does, however, clearly supinate when he throws his breaking ball. In combination with his forearm flyout, this action will eventually lead to discomfort (or worse) near the olceranon process of his ulna.

His follow through is pretty clean compared to most pitchers, but because he uses his pectoralis major to horizontally flex his humerus as most pitchers do, I have some minor concerns about future rotator cuff problems.

Despite the number of flaws discussed above, Boscan's mechanics are pretty typical for today's pitchers. Based on his mechanics alone, I would not say that Boscan is at any greater or lesser risk for arm injury than an average professional pitcher.

Ryan Tatusko. Drafted in the 18th round of the ballyhooed 2007 Texas Rangers draft class, Ryan Tatusko spent all of last season pitching for Low A Clinton. Tatusko features a low-90s fastball that might cut, sink, tail, or even be a little too straight. He calls his breaking pitch a slurve, but when I saw it, it looked like a good, hard curve ball.

On March 20, 2009, Tatusko toed the rubber in a AA spring training game. In the bullpen, his fastball was blazing and his slurve had a gigantic break. I was really impressed.

It was a bit of a different story once he climbed up onto the hill. The fastball looked like it was down a couple of ticks, and the slurve was inconsistent. If you've ever been a pitcher, you've probably had one of the opposite bullpen days.

The following clip was filmed at 210 frames per second, showing several pitches from the windup as well as the stretch.

Tatusko is a serious drop-and-drive guy. He gathers himself at the top and then sits down on his back leg before driving forward. The angle is rough, but it looks like he only lands slightly closed (which is better than more closed). After his drive, he pulls forward off the rubber to help keep his center of mass moving forward. This is excellent.

Tatusko also has a very good ball pick-up. It isn't quite the pendulum swing that I like to see, but he doesn't rely on powerful external rotation and the ball passes shoulder height before the elbow. This helps reduce the inertia of reverse forearm bounce, though, in Tatusko's case, it still has a presence.

He has some minor reverse shoulder rotation, but he has a nearly straight-line shoulder drive. Tatusko tilts his shoulders toward the glove side and really picks up his pitching elbow. By picking up his elbow, he limits the downward motion of reverse forearm bounce. As I said above, there is still a noticeable bounce, but Tatusko does a very good job of reducing it.

Tatusko's shoulder tilt also helps get his arm into a more vertical position which limits forearm flyout and allows for a greater kinetic contribution from the triceps brachii - another mechanical plus.

He appears to have good pronation on each of his pitches. This is hard to tell at only 210 fps, but I definitely do not see any supinated releases.

After Tatusko's primary arm deceleration, the momentum of his forearm pulls his humerus into his chest. The forces involved here are far less significant than during primary deceleration, so I think it looks worse than it really is.

To put all of this in perspective, Tatusko's promising mechanics do not guarantee that he will not suffer an injury. He has fewer risk factors, but nothing is written in stone. Overall, I really like how he throws the baseball.

When Stephen Strasburg took the mound in the bottom of the first inning, it was a very breezy 45° outside. By the time he was done, it was a brutally windy 39°. The wind was blowing straight out to left at Lupton Field, and when TCU second baseman Ben Carruthers hit an 0-2 pitch just beyond the outfield fence to lead off for the Horned Frogs, it looked like it might be an interesting night.

As it turned out, the Carruthers homerun was a blip. Strasburg responded by retiring the next 14 hitters in a row, 10 of them on strikes.

Game: March 27, 2009 vs. TCU

Fastball. 91-99 mph. Strasburg fought with the wind in his face all night but maintained command and got ahead of hitters all night long. He started in the mid-to-upper 90s, but fell to 91-94 after the fourth inning when the wind really picked up. I don't think his body was responding well to the cold, and his fastball command suffered causing him to work off his curveball in the late innings.

Curveball. 81-84 mph. Even when the TCU hitters guessed correctly, they had little chance of squaring up on this pitch. Throughout the night, Strasburg located it with ease, throwing it wherever he pleased. TCU hitters chased it out of the zone all night.

Change up. Rarely thrown. I saw a pitch at 87 mph and a couple in the mid-70s. I'm not sure which was his change up or if either pitch actually was his change up. He was essentially a two-pitch pitcher for all 8 innings.

Mechanics. Strasburg has very traditional mechanics with excellent hip and shoulder rotation, but with what looks like a rough follow through. The clip below shows 4 pitches at 210 fps and 2 pitches at 420 fps with at least one fastball and one curveball at each speed. (Kyle Boddy at DrivelineMechanics.com took a brief look at Strasburg's mechanics this past winter.)

Strasburg starts his delivery with an easy leg pick-up. He then gathers himself before stepping forward and really driving off his back leg. Right before he lands, he turns his front hip to square his landing leg to the plate. He has a soft landing on the ball of his foot, but he then drives backward with his landing leg. This creates great hip rotation but stops his center of mass from moving forward.

Strasburg does not use a pendulum swing to pick up the baseball. He takes the ball behind his back and accelerates it toward third base as he brings the ball to driveline height. His flexed elbow moves well behind his back and reaches shoulder height before the ball. From there, he must forcefully externally rotate his arm to get the ball to driveline height. This causes late forearm turnover and increases the valgus torque that occurs during reverse forearm bounce. This is a risk factor for his ulnar collateral ligament.

When Strasburg's center of mass stops moving forward, his trunk flexes forward while his shoulders rotate and his elbow again moves far behind his shoulders. He drives his pitching shoulder all the way through his release. This is excellent, but it doesn't stop his arm from finishing violently across his chest. (At full-speed you can see his arm "bounce" off his rib cage.) This is a risk factor for the supraspinatus and the infraspinatus muscles of the rotator cuff.

One major plus in Strasburg's mechanics is the apparent pronated release of his curveball. It is definitely hard to see in this video, but the second to last pitch is your best chance to see it. As he releases the pitch, Strasburg's wrist quickly moves from a supinated to a pronated position. This allows him to powerfully drive the top of the baseball instead of pulling the ball down with a supinated grip. By doing this, a curveball is thrown with more velocity and better rotation.

Overall. Stephen Strasburg is a 6' 4", 220 lb beast of a pitcher. He has two plus-plus pitches right now and ace-quality command. He's putting up numbers that would have Mark Prior and Jered Weaver blushing. Whether or not he is picked by the Washington Nationals as the first overall selection in the 2009 MLB First-Year Player Draft, he will certainly command the largest contract.

Strasburg has some of the common flaws of traditional pitching mechanics and carries with him the associated risks. These risks will almost certainly not affect his draft status because it could be 10 years before anything goes wrong. Predicting injuries is folly, but identifying risk is always important.

In a few months, Mr. Strasburg will be a very, very rich man.

Richard Alvarez. The Texas Rangers signed right-handed pitcher Richard Alvarez out of Venezuela during the International Signing Period in 2008. Jamey Newberg recently called him "the prize of the Rangers' 2008 Latin American haul," and at least one pre-signing scouting report had his fastball as high as 92 mph to go with a curveball and a change up.

On Thursday, March 19, 2009, Alvarez took the mound in the Low A minor league Spring Training game on the back fields of the Rangers' complex. In his 1 inning of work, Alvarez featured an extremely lively fastball that sat at 84-86 mph. He turned his change up over well and kept it away from the middle of the plate. The 1 curve I saw him throw was bounced intentionally for a swinging strikeout and it still looked above average.

When asked about Alvarez's velocity, one scout told me Alvarez was in the upper 80s and touching 90 after signing in 2008. Alvarez will likely hang around Surprise for several months before breaking with the short-season rookie club leaving him plenty of time to build up his arm strength and get his velocity back into the upper 80s.

Mike Hindman of InsideCorner estimates that Alvarez is about 6' 0", 170 lbs, but my impression is that both of those numbers are generous. As a 16-year-old kid, though, Alvarez certainly has room to grow. Here's your first look at Texas Rangers right-handed pitching prospect Richard Alvarez.

Very briefly, Alvarez has a late forearm turnover. It doesn't even reach vertical until after he starts to open his front shoulder. The inertia that turns his forearm over also creates some reverse forearm bounce, but his shoulder tilt helps him pick up his elbow and reduce forearm flyout. Alvarez drives hard off the rubber, but then drags his right leg stiffly after landing. He drives his shoulder through the pitch for great shoulder rotation, but he still has quite a bit of arm recoil after every pitch.

Even though this sounds pretty negative, these are problems found in most pitchers with a traditional delivery. There are things he could be doing better (forearm turnover and arm recoil), but there really isn't anything dramatically alarming about Alvarez's mechanics.

Pedro Strop. In April 2008, while in the Colorado Rockies' system, Strop was diagnosed with a stress fracture in his pitching elbow (most likely the olecranon of his ulna), and he missed the rest of the season. The Rockies designated him for assignment in September, and the Rangers signed him to a minor league contract in early November. In 2007, Strop's numbers were slightly above average for a player who had been pitching his entire life, but it was Strop's first full season as a pitcher. His strikeout rate was an amazing 12.3 per 9 innings. (Note: Strop's 2007 season was cut short by elbow tendonitis in early August.)

The Rangers have brought him along slowly this spring, and he stepped to the mound on March 17, 2009 in a Double-A minor league Spring Training game. I turn to Mike Hindman for the scouting report, "He deals a 94ish fastball with a lot of armside run, a power slider at 84-86 mph and a nasty splitter." In his 1 inning of work, Strop was all that he was cracked up to be.

In January, Kyle Boddy took a look at Pedro Strop's unique arm action. Here's some high-speed (210 frames-per-second) video from Strop's outing. (Sorry about the shaky frame; it's hard to hold a camera still when one of your arms is in a sling.)

I am concerned about Strop's health going forward. He's struggled with arm health since the end of his first full season as a pitcher, and based on this older video, it doesn't look like he plans to change his mechanics. I like the way he uses his body (good drive, landing, hip and shoulder rotation), but his arm still seems to do the same things that led to the injuries that caused him to miss almost all of the 2008 season.

Kendal Volz is a 6' 5", 225 lb right-handed pitcher with some monster stuff. Out of Smithson Valley HS (TX), Volz was among the top college juniors available for the 2009 MLB First-Year Player Draft. Baseball America pegged him as the #6 prospect on both the juniors list and the overall college list.

Volz spent the summer working as Team USA's closer allowing only 1 unearned run in 14 innings and going 8-for-8 in save chances. He works off a low-to-mid 90s fastball, a hard slider, and an improving change up.

At the Houston College Classic, Volz took the mound for Baylor University against UCLA.

Game: February 28, 2009 vs. UCLA

Fastball. Volz sat in the 87-90 mph range throughout the afternoon, a sizable drop from his 2008 velocity. Though Volz told Aaron Fitt that he thinks his velocity will return, I think there is reason for concern simply because the drop is so large. That said, it was a pretty cool day in Houston, and I won't be shocked if his velocity does return. The pitch still had great sink and some arm-side action. He showed only college-average command.

Slider. Volz's slider looks like a tight curveball with more downward action than sliding action, but not quite an 11-to-5 break. The pitch is definitely a plus. He was throwing it in the upper 70s and touching 80 with it. The break is big and sharp. He throws it with confidence and with very good command. According to Fitt, he threw more sliders (47) than fastballs (41).

Change up. The change up didn't see much action, but again, Volz threw it with confidence and command. There was good sinking action to it, but I didn't note any arm-side fade. In the low 80s, it only had a 6-8 mph separation from his fastball. To be Major League average, the pitch needs either more movement or a greater drop in velocity.

Mechanics. The video shows a classic tall-and-fall pitcher whose forearm never fully lays back.

Volz's delivery starts with a prototypical balance point after he picks up his front leg. His back leg remains stiff as he steps into his stride. When he lands, he lands slightly closed and so abruptly that he actually kicks dirt toward the plate. Volz uses this to drive his hip turn and kick start his shoulder rotation which are both good. He drags his back foot off the rubber, so his hip turn could be even better.

To pick up the ball, Volz starts with a reach back by flexing his wrist but manages to avoid bringing the ball behind his back. His elbow reaches shoulder height before the baseball but not by much, and at foot plant, he is still picking up the ball with his forearm 180° from the laid back position.

This leads to a late forearm turnover, though Volz's forearm never fully turns over. At 210 frames per second, it's hard to see clearly, but it appears that his arm only rotates about 50° to 60° behind vertical. This fairly short lay back is accompanied by some wrist extension (see photo).

By flexing the muscles on the posterior of the forearm (extensor muscles), Volz increases the valgus stress in his ulnar collateral ligament, putting it at risk. To protect the UCL from damage, valgus stress must be reduced; increasing this stress is never a good idea.

As he finishes picking up the ball, Volz brings his elbow behind his back creating a lateral "whip" in his arm action. When his shoulders start to rotate toward the plate, his pectoralis major flexes and drives his elbow toward third base. His hand follows, and this results in forearm flyout.

Volz shows good pronation after release, but only pronates into his release when he throws his change up.

He drives his pitching shoulder all the way through his release, and this creates a very controlled follow through. His arm wraps slightly across his body, but this occurs after primary deceleration and with almost no recoil.

Overall. Expected to be selected in the first half of the first round, Volz has probably slipped into the back end of the supplemental round and possibly further than that. His 2008 fastball is not there, and his command has been unpredictable - 12 walks, 8 hit batters, and 22 strikeouts through 26.1 innings pitched. Still, he has been tough to hit - limiting opponents to a .157 average - and his ERA is a very respectable 2.73.

Volz's current struggles - drop in velocity, lower strikeout rate, and bouts of wildness - are typical of a pitcher dealing with an elbow injury, and having looked at his mechanics in slow motion, I believe this could be the case. His command and velocity will be under the microscope until the draft rolls around.

If Volz falls too far on draft day, he has the option of returning to Baylor for his senior season; however, if he can iron out his command issues over the next couple of months and show scouts what he showed them last summer, he will re-establish himself as one of the best pitchers available.

After missing the 2008 season while recovering from Tommy John surgery, Alex Wilson has been busy re-establishing himself as a top prospect. As a freshman at Winthrop University, before his injury, most reports said Wilson featured a 91-94 mph fastball and a plus slider.

Fully recovered and at Texas A&M University, Wilson ran his fastball up to 98 mph this fall according to Baseball America. The publication pegged Wilson as the #24 ranked junior and the #26 ranked overall college prospect for the 2009 MLB First-Year Player Draft.

The 6' 1", 205 lb right-hander pitched against Rice University on February 28, 2009 at the Houston College Classic.

Game: February 28, 2009 vs. Rice University

Fastball. Wilson worked pretty comfortably in the 92-94 mph range with his fastball and occasionally a tick higher. His command came and went throughout the outing. In my notes, I wrote "command" early, only to scratch it out an inning later. In the 4th, he gave up a triple, walked two batters, and hit another. Outside of that, he was quite spectacular.

Slider. This is definitely a plus pitch. Combined with his fastball, Wilson recorded 15 of his 18 outs either on ground balls or by strikeout. The pitch has a solid, late break, and Wilson spotted it very well in this outing.

Other pitches. Wilson threw something that looked like a slow, lazy curve a few times. I haven't read any reports about a curveball from Wilson, so it's possible that this was a mistake slider or a horrible change up.

Wilson also threw his change up several times, and he admitted to Aaron Fitt that it was "probably [his] least effective pitch." It was basically a "show me" pitch, but it served its purpose.

Mechanics. Again, it looks like we have a guy who lands closed. He has a clean pick up and what is typically a very good follow through.

Wilson stays tall as he gathers himself at the top. Wilson starts to drift forward then bends his leg and gets a great forward push onto the ball of his landing foot. He drags his back foot off the rubber instead of pulling it, but his bent front leg doesn't completely stop his center of mass from moving forward.

Wilson's landing limits his hip rotation; you can see that his hips aren't square to the plate until well after pitch release. This does not cut off his shoulders, however, since he uses his trunk to drive his throwing shoulder almost directly over his front hip. Tim Lincecum has a very similar trunk flexion in his delivery.

To pick up the ball, Wilson swings his arm down, back, and up, like a pendulum swing, but he does not supinate or turn his forearm over. Wilson's elbow and hand reach shoulder height at about the same time, but he flexes his elbow as he horizontally abducts his humerus. His forearm is nearly vertical at foot plant, and that leads him to a late forearm turnover.

Because he drives his shoulder straight forward over his front hip, he does a good job of limiting the lateral component of his delivery and of minimizing forearm flyout. Wilson picks his elbow up a little, limiting the reverse forearm bounce, and really drives the ball with his triceps.

On some of his pitches, Wilson throws with a low 3/4 arm slot and has a large lateral component in his delivery. His forearm flyout on these pitches limits the contribution from his triceps. On these pitches, he has a more significant reverse forearm bounce. I captured two of these pitches in the clip above, but it's hard to tell which pitch is being thrown.

Wilson seems to pronate very well and very consistently. This is especially true when he turns over his change up.

His follow-through varies with his arm slot. Wilson's higher arm slots result in a cleaner follow-through, and most of Wilson's pitches seem to be thrown from this slot. When his arm drops into the low 3/4 slot, his arm has a tendency to move across his body during follow-through; however, his strong shoulder drive helps take a lot the lateral deceleration stress off his rotator cuff by limiting the degree of horizontal shoulder flexion during deceleration.

Overall. This particular outing, which featured a very wild inning, was sandwiched by two starts in which Wilson utterly dominated the competition - 14 strikeouts in each game. Through his first 3 starts, Wilson has allowed only 9 hits and 5 walks in 18.2 innings while striking out an amazing 35 batters.

He has two average-to-plus Major League pitches in his slider and fastball, and at times, each is a solid plus pitch. Both have the potential to be even better down the road as he further distances himself from Tommy John (ulnar collateral ligament replacement) surgery.

Wilson's mechanics are not perfect, though they may be better now than they were prior to his injury. He has some of the common flaws of the traditional delivery, but it's hard to say if those will cause him trouble down the road. As a pitcher with a significant injury in his past, Wilson will always carry injury questions with him.

Alex Wilson has only improved his draft stock so far this season. Right now, he looks like a very solid 1st round pick. If he keeps doing what he's done so far, he could be a top 10 pick before June rolls around.