Better Know a Red: Keyvius Sampson

RHP Keyvius Sampson made his MLB starting debut on Sunday afternoon with a well-pitched ballgame against the Pittsburgh Pirates.  Sampson was not a guy on my radar, but he impressed me with good velocity and a nice-looking curveball that he seemed able to throw for strikes.  Here's a profile on the latest Reds rookie to debut in their starting rotation.

Player Profile: History and Statistics

Sampson was drafted in the 4th round of the 2009 draft by the San Diego Padres out of Forest High School of Ocala, Florida.  Sampson is the 3rd major leaguer to hail from his school, joining Reid Nichols ('80-'87) and Jonathan Johnson ('98-'03).  Sampson was promoted all the way to low-A during his first season, albeit only for two games (on start).  The next year, he also threw for the Padres' low-A team, though again in limited action (10 starts, 43 innings).  By 2011, as a 20-year old, he was pitching for their A-ball affiliate, and he progressively was promoted a level per year, reaching AAA by 2013 as a 22-year old.  His minor league career started off brilliantly, with outstanding strikeout rates and acceptable walk rates to go with generally dominant performances.  Marc Hulet ranked him as the Padres' #6 prospect prior to the 2014 season, praising his velocity and noting he had a "potentially plus slider" and a quality change-up, but inconsistent control.

However, once he reached AAA, the more advanced hitters at that level seemed to have the distinct upper-hand. From 2013-2014, he posted an ERA in the high 6's, with a very comparable FIP.  The most obvious problem was that while he continued to post good strikeout rates, his walk rates ballooned to almost 7 bb/9.  In his offseason look at the Padres, Kiley McDaniel again praised Sampson's velocity and change-up, but expressed major concerns about his command and his slider.

The Padres put him on waivers this offseason, and the Reds grabbed him in January.  This year, in limited action the Bats, he hasn't been much better.  His walk rate has "improved" to 5 bb/9, but his strikeout rate has also slipped a bit.  He was doing well at avoiding the long ball, but that could easily have just been luck--in his first game with the Reds, he posted high fly ball rates (36% ground ball rate), although he had a dandy 6:1 k/bb ratio in his six solid innings of work.  The question with Sampson clearly seems to be whether he can avoid walks well enough to let his stuff play up.  Stats:

Repertoire

Given the scouting reports, I expected to see fastballs, change-ups, and sliders.  But this is what we saw:

I don't know if the curve is a new pitch for him or not.  The FanGraphs minor league guys always focused on his other pitches, but this tidbit from mlbtraderumors on the day he was DFA'd by the Padres this offseason mentions him scrapping the pitch.  Nevertheless, Sunday he was throwing it 23% of the time, and to great effect: Brooks Baseball describes it as generating an "extremely high number of swings and misses" compared to other curveballs.  It is the pitch that stood out to me watching him.  I saw him drop it in for a strikeout looking, and then saw it drop into the dirt to induce a chance.  The pitch looked great; hopefully he can repeat that next time.

It's tempting to go further with this, but with only one start to chew on I think it'd be grasping for signal amongst too much noise.  The challenge for the Reds, and for Keyvius Sampson, will be to keep him throwing the ball over the plate over the remainder of the year.  If he can do that, I'd wager he has the stuff to have some success.  If not, things won't be pretty.

Did Burke Badenhop Find His Velocity?

Burke Badenhop was the Reds lone free agent signing this past offseason who received a guaranteed big league deal.  I heralded it as a superb signing: a highly effective, ground-ball machine for the bullpen with a very low salary.

Instead, he's been a disaster.  His velocity was way down at the start of the season (~87 mph on his fastball, vs. ~89-90 mph in 2013-2014), his already-low strikeout rate plummeted, and it seemed his lack of velocity also reduced the effectiveness of his sinker.  While watching last night's game, however, I noticed him regularly hitting 90-91 mph, he managed a pair of strikeouts on fastballs up in the zone, and worked around an error by Brayan Pena on a squibber in front of the plate.

Here are Badenhop's velocity measures, by game, this year and last year:

Over the last 5-7 games, his velocity has taken a big jump from where it had been in April and most of May.  It's back comfortably around 90 mph, though maybe still a slight tick off of where he averaged last season.  His results have been been a little bit better too: 4 K's and 2 BB's in 5 innings over his past five appearances, with 1 run allowed:

It's too early to know if he's really back.  But if Burke Badenhop can return to his 2014 form, it would be a nice shot in the arm for the Reds' bullpen.

Better Know a Red: Kevin Gregg

Photo Credit: Keith Allison

Kevin Gregg was signed on a minor league deal over the offseason, and yesterday was added into the major league roster in a surprise decision to take him over Sam LeCure.  Gregg, along with fellow newcomer Burke Badenhop, will be counted on to help turn around the Reds 2015 bullpen after a rough year in 2015.  As a guy with 177 career saves to his name, he would seem to bring some pedigree.  He entered pro-ball, however, as a 15th-round selection out of Corvallis High School, Oregon, when the Oakland Athletics took him in 1996.  It wasn't until 2003, however, that he made his big league debut after becoming a six-year minor league free agent and then ultimately signing with the Anaheim Angels.

Throughout his minor league career, he was primarily a starting pitcher, but it wasn't until 2004 with the Angels as a 26-year old that he finally was tried in the major league bullpen.  He was reasonably effective in two of his three seasons with the Angels, but then was traded in the pre-2007 offseason to the Florida Marlins in exchange for a younger Chris Resop.  There, the Marlins tapped him as the closer, a role that he would hold for at least part of six of the next seven years for five different clubs.  Here are his career stats:

To be honest, Gregg's career as a closer seems like a shining example of how a mediocre pitcher can put up pretty nice save numbers.  He's had some good seasons.  In 2010, for example, he posted an 84 ERA- to go with his 37 saves for the Blue Jays.  But over 2007-2011, his stint as a more or less full-time closer, was marked by an ERA only about 10% better than average (89 ERA-).  He has always posted decent to excellent strikeout rates, but he has also almost always had poor walk rates and, often, fairly poor ground ball rates to boot.  His stats profile looks like the classic hard-thrower who doesn't know where it's going.

I was surprised to learn, therefore, that he really doesn't throw that hard.  He's a big guy (listed at 6-6, 245 lbs), but his highest average fastball velocity was in 2008 when he threw 93 mph.  That number has been falling in recent years, and was in the 90-91 mph range the last few seasons.  So what does he throw?

He throws a pretty full complement of pitches, which is probably how he stuck as a starter through the minors.  It also seems like a pretty good indication of why he was tapped as a closer so often: if a team doesn't have a dominant pitcher, they should at least look to someone who can get batters from both sides out.  The mix of a splitter, cutter, and curve-ball gives him weapons that break both directions on the plate, which means he should be effective against both righties and lefties.  That fits his results, too: over his career, he's allowed a .311 wOBA vs. left-handed batters and a .320 wOBA vs. right-handed batters.  That's a reverse split, with about 1500 batters faced in each case.

His cutter seems a little slider-like to me, especially given how much slower it comes in than his true fastball.  It has a little bit of rise to it (~7" vertical rise), however, so "cutter" seems like a good definition of the pitch to me.

One thing that did catch my eye with his Brooks pages, however: Gregg's velocity has been up this spring:

It's not a big spike.  But after being down the last few years, his spring average of 93.2 mph is his best monthly mark since June 2011 (93.6 mph).  I imagine that helped his cause a bit with the Reds opting to take a flier on him.

2015 Outlook

Gregg is entering his age-37 season, and his projections are ugly.  Steamer projects a 4.18 ERA.  ZiPS projects 4.64.  He is coming off season-ending surgery last August to remove bone chips in his elbow, a similar procedure (if memory serves) to what Mat Latos had prior to the 2014 season.  His velocity seems good this spring, based on a handful of pitchf/x games, and the Reds seem happy with his performance.

If he's right, the dream is that Gregg can provide quality middle-relief against batters from both sides of the plate.  And yeah, sure, maybe he's got another quality season in the tank.  The concern, of course, is that if he can't keep his walk rates down (and he usually can't), his fly ball tendencies might lead to some big innings for the opposing team.  There's not much else that we can do other than hope, at least, that he can down the fort long enough for Sam LeCure to figure things out in AAA.

Reds sign Burke Badenhop

Yesterday, the Reds signed their first "big" free agent of the offseason in right-handed reliever Burke Badenhop.  Badenhop, who turned 32 years old today, has been a member of five different organizations since being drafted in the 19th round by the Tigers in 2005.  The signed a 1-year deal with the Reds for a total of $2.5 million guaranteed, with a mutual option for 2016 that can bring the total value of the deal to $5 million.  That's paying for something shy of 1 WAR spread over two years, even assuming the Reds pick up his option.  Seems like a nice deal to me.

Stats:

Badenhop seemed to make an adjustment in approach with the Rays in 2012, decreasing both his strikeout and walk rates substantially.  This trend has continued in the years since, with an even larger drop in strikeout rate last season with the Reds Sox.  In addition to his superb control, however, what has made him successful is his excellent ground ball rates, which climbed all the way to 61% last season with the Red Sox.  Low walks and lots of ground balls should work well with the Reds' strong infield defense, so I like the signing a lot.

When I posted as much on twitter (albeit with a typo in Badenhop's name!), RJ Anderson sent me the following tweet:

@jinazreds Love him. Smart dude, too. Uses Brooks all the time. Does this awkward walk around between pitches.
— R.J. Anderson (@r_j_anderson) February 8, 2015

Cool, right? Since he looks at Brooks Baseball lets do that too!  First, his pitches (2012-2014):

He throws a sinker, change, and slider.  There are a grand total of 7 fourseam fastballs on his record in the past three years, and you can see they do cluster away from his sinkers in spin axis.  Here is his actual pitch usage:

So, we're looking at 75% sinkers, with a small number of sliders and change-ups mixed in.  He seemed to experiment with adding more sliders in 2013, and then seemed to almost abandon it in favor of his change-up last year.  As you'd expect, he throws more change-ups against lefties, and last year almost threw as many change-ups to lefties as his sinker!

Finally, one last thing.  As expected, given the decrease in his walk rates, we're seeing a general increase in his tendency to locate pitches in the strike zone over the past three years compared to the years before:

Summary Opinion 

While it's great when you can have strikeouts, I think ground ball, low walk rate pitchers should be a good match for the Reds' defense and park.  Badenhop looks like a great pitcher to come in against a right-hander with a man on first to induce a double play.  He's immediately in the running for second-best Reds' reliever, and should be a nice setup guy for us this season.  I'd think he's a good bet to be worth ~1 WAR per season in value, which is a lot less than the Reds are paying him.  Even at 32 years old, I like this signing a lot.

Chapman abandons change (mostly)

So, less than two weeks ago, I wrote about how Aroldis Chapman's improvement this year can arguably be traced to the debut of his change-up.  Well, as Jeff Sullivan noted, almost coinciding with when I wrote that, Chapman now seems to be moving away from using his change-up.  In fact, he's thrown the pitch in only 1 of the last 5 games, and 2 of the last 8:

The reason appears to be that he has a hard time throwing the change-up for strikes.

The good news was that while he was not throwing it for strikes, he was usually missing down (assuming he was even trying to get it in the zone).  Nevertheless, it does look like the pitch has fallen out of favor.  So much for my last piece on him! :)

I personally hope that he can continue to work it in, even as a show-me pitch.  Hitters can catch up to his fastball if they know that it is coming.  The slider is a fantastic pitch, and I'm sure he can be quite successful as a fastball/slider reliever.  But a third pitch against right-handers, at least, would be one additional thing that hitters need to keep in their minds as they step in to face him.

The New Aroldis Chapman

The Reds' worst-kept secret is how amazing Aroldis Chapman has been this year, and the story of what he is doing differently to become so dominant.  Chapman is arguably in the midst of the best season of his career:

(sorry about the size of that one--click to make it bigger).

I know he had the 1.51 ERA is 2012.  But his strikeouts are at to 2 k/inning (18 k/9) on the season, his walks are stable, and he's allowed just one home run on the year.  He's been ridiculous***.

***This calls for a graph dump!

So how has he done it?  Well, part of it is that his velocity is up about two mph this year after averaging "just" 98 or so the prior three years.  Here's Brooks' Baseball's graph of that:

Aroldis has had months in which he has averaged over 100 mph.  But he's never had three consecutive months like this before in terms of sheer power.

The other thing that appears on this graph, of course, is that Aroldis is throwing his change-up again for the first time since 2010.  Here's a look at all of his games on the year in my favorite plot for identifying pitches:

It's pretty straightforward.  Chapman throws crazy-hard, with a fastball that breaks back away from a right-handed hitter while traveling at roughly the speed of sound.  And on top of that, he has a change-up that breaks almost 10 inches away from a righty, and then a slider that breaks in toward the right-handed batter's back foot.  The change-up and slider break opposite directions and travel roughly the same velocity.

Chapman is throwing both of his secondary offerings much more often this year:

After living almost exclusively with this fastball at times from 2011-2013, he's dropped his usage of that pitch into the high 60% range.  Instead, he's now throwing a quarter of his pitches as sliders, and is working in change-ups at a consistent, low rate.

The change-up has been very effective for him:

When he first started throwing it in May after coming back from the DL, batters had no idea what to do with it, and were swinging and missing 50% of the time he threw it.  They've since learned to lay off it (because they can't hit it: the pitch has a 95% whiff rate when they do swing on the season!!), and so we're seeing that whiff rate decline.  But, concurrently, we're seeing a spike in his fastball whiff rate.  So far in July, his fastball has induced the highest percentage of strikeouts of any month in his career.  It's correlational, but it sure looks like the use of his change-up has strengthened the impact of his fastball.  'Cause the fastball wasn't already an amazing pitch....

One last thing: on a recent Redleg Nation Radio, Bill Lack asked whether Aroldis gets beat more often when pitching down in the zone than when pitching up in the zone.  Here is are opposing batters' slugging percentages against Chapman in different parts of the zone.

First, left-handed batters:

(also known as "good luck, fella").  Lefties have gotten good wood on the ball when throws in the strike zone down and away, but otherwise are basically hopeless against him.

Now, right-handed batters:

Bill's perceptions hold true here.  When Chapman is throwing in the bottom half of the zone against righties, he's actually been hit pretty well during his career.  When he elevates the ball, however, it's been pretty much lights out.  And this isn't the pattern you always see either.  Here's a link to Cueto's graph; he gets it up in the top part of the zone as well.


Chapman seems to have noticed.  This year, he's throwing up in the zone more than in prior years, especially with his fastball:

All of Chapman's success this year is made all the more amazing by the fact that he suffered a serious head injury in spring training.  He's been one of the bright spots on the team thus far.  I don't know if he'll still be on the team by the end of the year, as he would seem to be a nice trade chip if Jocketty decides the Reds need to sell off some parts.  I think someone would overpay for him.  But it's fun to enjoy him while he's still a member of the Reds.

All graphs courtesy of the amazing Brooks Baseball.

Cameron: Johnny Cueto's Fastball Unhittable

Dave Cameron pointed out today that a big part of what has made Johnny Cueto so amazing this year is that his four-seam fastball has been nearly unhittable:

I mean, sheesh.

Cueto is known as a sinkerballer, and that's still very much what he is.  His ground-ball percentage still stands at 53%, and he still throws his sinker a healthy portion of the time (22.5%).  But Cueto has been seeing uncanny results with his four-seam fastball, which he is throwing a bit more often this season:

***Note also: Tony Cingrani also appears on this graph of low wOBA allowed.

That increase in his four-seamer frequency seems to part of why he's showing a 1 mph increase in his "fastball" velocity this season, although all of his pitches are seeing small velocity increases:

I tend to expect that outliers as substantial as Cueto is in that first graph are due for a regression.  That shouldn't be a surprise, because Cueto has been so unbelievable this year.  It's pretty rare for a pitcher to be almost twice as good as everyone else on something.

Nevertheless, the Dodgers announcers were talking a lot about Cueto and the deception in his delivery last night.  I think that Cueto's increased velocity, coupled with the deception of how well he hides the ball during his delivery, are a bit part of why he's been able to accomplish what he has this year.  As Cameron states, this is not just a BABIP-inspired oddity.  I can't explain it either, but I am enjoying the ride.

Cueto's Velo On the Rise

As C. Trent noted in his wrap from last night's game, Johnny Cueto's fastball velocity is on the rise.  Here are his game-by-game fastball velocities over the past two years:

And last start, he actually threw harder as the game went on:

That's crazy.  And very exciting.  Cueto is having an extremely special season right now.

Now, I will say that I have seen some claims that spikes in velocity can precede injury.  The logical argument is unclear to me, but I think(?) the idea is just that extra velocity = extra strain = extra risk.  But the only evidence I've seen for this was Matt Harvey's 2013 season.

In any case, I'm choosing to be excited about this.  Cueto has been beyond fantastic this season, and I'm enjoying every minute of it.

Tony Cingrani is Mixing Pitches, but Missing Zone

In a excellent piece last week, Eno Sarris described Tony Cingrani's efforts to expand his repertoire this year.  Last year, Cingrani threw 81% fastballs.  This year, he is mixing in a few more sliders and change-ups into his offerings, and his fastball rate is down to a far more normal 72%.  Here are his usage patterns over the past two seasons:

It's not a radical departure from past seasons, really.  But this season, he his average fastball rate has been right about where his minimum was last year, around the 75% mark.  We've seen a corresponding increase in his use of his change-up and his slider.  Here are his pitches from his career, 2013-2014:

All of the curves shown here were from 2013, and stopped throwing it by August of last year.  At this point, he's a Fastball/Change-up/Slider pitcher.

How has he done?  Here's his FanGraphs line:

So, his ERA has been fine...but that might not be sustainable.  His xFIP and SIERA are showing a pretty substantial decrease in effectiveness, both showing up with an estimated ERA of about 4.20.  His strikeout rate is down very slightly, as is his swinging strike rate.  But the biggest concern has to be his walk rate, which is sitting at a pretty horrible 5.24 bb/9.  The main reason that his ERA is not higher, probably, is that his BABIP is 0.226.

Given the change in repertoire, the question that came to my mind is whether he is missing with those extra pitches that aren't fastballs, and that's driving his walk rate up.  So, let's look:

Tony Cingrani 2013 Pitch Outcomes

Tony Cingrani 2014 Pitch Outcomes

If anything, he's actually showing slight improvement in his ability to get his change-up over for a strike (or, alternatively, to induce a swing when it's thrown out of the zone).  Furthermore, as Eno noted in his article, his whiff rate on his change-up is up substantially this year (8% vs. 3%), as is his ground-ball rate (not shown, but it's 14% this year on change-ups vs. just 4% last year).  Both of these are good, encouraging things.

The issue with his walks seems to be that he's missing the strike zone with his fastball and slider more this year than he did last year.  He throws his fastball so much more than other pitches, that 6% jump in ball rates (39% vs. 31%) on his fastball seems to be the main culprit.  Cingrani doesn't have to be a guy who pounds the zone.  Nevertheless, he will need to get his walk rate under control if he is to have continued success this season.  Here is another look at the same thing in graphical form:

So, the good news is that while he hasn't exactly been a model of control this season, the good news is that (aside from his Chicago start) he hasn't been disastrously away from what he did last year in terms of where the ball arrives in the zone.  I'm not panicking, but I am raising my eyebrow, and will be watching this moving forward.

Another thing I noticed on Cingrani's FanGraphs page is that his fastball velocity is down by about 1 mph in the early goings.  Sometimes, this can indicate a loss in effectiveness.  That said, there's an easy and benign explanation for this:

Cingrani had a nice jump in his velocity last season in June of last year.  That, not coincidentally, is when Cingrani was pitching out of the bullpen (June 17 to June 28), which we often see when pitchers move from the rotation to the bullpen.  His velocity this season has been more or less right where it was at the end of last season.  While I'm certainly  hoping to see it rise a little bit as the summer heats up, he's not terribly outside last season's norms.

I'm not sure that there's a clear conclusion to be had, here.  Cingrani is doing some good things this year: he's mixing in more pitches to offset his fastball, and he's still missing bats at an excellent rate.  But his control has been iffy, particularly in his most recent start, which is something that he will have to address moving forward if he is to continue to have success.

Catcher Framing is a Thing

Devin Mesoraco isn't bad at framing.  But
it's an area where he can improve.
Photo credit: Shawna Pairan

Arguably the biggest change that occurred in the time that I was away from blogging has been the growing realization of how important catcher framing is.  While some of the initial studies were dismissed because of preposterous effect sizes, subsequent work--though more conservative--has found that nevertheless catcher framing is really important...so important that it can completely dwarf the catchers' other contributions, including their offensive contributions.

I've had a longstanding interest in catcher fielding.  At one point, I developed my "own" catching metric that inadvertently converged on work of Chris Dial in an effort to evaluate overall catcher performance due to stolen bases, errors, passed balls, etc.  But I'm way behind on this framing stuff.  Here's an attempt to catch up.

The Data

Last month, Harry Pavlidis and Dan Brooks pushed out a new set of catcher framing statistics that they call RPM (for Regressed Probabilistic Model) framing.  They seem very rigorous.  They are WOWY measures (to account for pitcher influence), include adjustments for umpires, and are regressed to the mean.  Their top-10 table is pretty interesting for Reds fans:

2008-2013 Catcher Framing Leaders, per 7000 opportunities (~1 year)

Jose Molina	35.9
David Ross	32.8
Yasmani Grandal	32.4
Jonathan Lucroy	31.0
Chris Stewart	28.3
Gregg Zaun	23.8
Mike Zunino	23.5
Ryan Hanigan	23.3
Carlos Corporan	22.3
Brian McCann	22.2

Those are totals for 2008-2013...and wow.  Not only was Ryan Hanigan brilliant with his arm, but he also provided outstanding value with framing.  I think it's interesting to see David Ross there near the top, who is another long-standing favorite of mine.  Also right there at the top, despite far less playing time, is former Red farmhand (and exchange currency for Mat Latos), Yasmani Grandal.

But more than the names, look at the magnitude!  +36 runs for Molina?  +23 runs for Hanigan?  That's worth ~3.6 and 2.3 wins apiece!  The swing is something like 50 runs per season.  Honestly, I can hardly believe the size of this effect, and it certainly makes me regret that Hanigan trade--despite my hopes for Devin Mesoraco this year.

And you can see what the Rays are doing here: if Jose Molina and Hanigan can keep doing what they do this year, it (almost) doesn't matter what they do on offense--they're bound to be above-average players.

Also, since they'd already done it for catchers, they can do it for the pitchers as well!  Here's the top 5:

Tom Glavine	40
Tim Dillard	21
Mariano Rivera	20
Francisco Cordero	20
Sam Lecure	18

Heck, yeah, Sam LeCure!  I think it must be the facial hair.  Plus, the guy is unquestionably crafty.  For a right-hander.

Projecting Framing

On Monday, Harry published a set of catcher framing projections for the coming seasons.  Because the RPM data are already regressed, they were able to use a simple 3-2-1 weighting on past years to generate projections for 2014 catchers.  The highlights for Reds players:

Brayan Pena: +4.4 runs
Devin Mesoraco: -6.6 runs

I *think* these are based on projected playing time, rather than a full season of play.  Therefore, Pena is probably a bit better than his +4 rating would suggest.  Last year, for example, he was a +3 player in a half-season of play.

FWIW, Ryan Hanigan projects a +18 runs/season.

I'm going to add these projections to my series preview spreadsheets.  For most players, it doesn't matter much.  But for some, it makes a big difference.  For example, Friday night during the Reds broadcast, Chris Welch correctly pointed out that Travis d'Arnaud is an excellent pitch framer.  He projected as a +16.6 run framer in Harry's data.  Adding that to his other projections pushes his fielding projection to +16 runs, and his WAR projection shoots from +2.5 WAR all the way to +4.1 WAR.  It's a huge boost, but I can't see any reason to discount those projections.

At the team level, with both Jose Molina and Ryan Hanigan behind the dish, the Rays are projected to be +40 runs (4 wins) above average, by framing alone.  It's really impressive.  Catchers are really important.

Catcher Height Matters

One last thing.  Last April, I was listening to an episode of Ben Lindbergh and Sam Miller's excellent Effectively Wild podcast, which was my main link to baseball last season (and is mandatory listening).  On it, Ben mentioned a study that he did that checked whether catcher height was related to framing skill.  In particular, he found that taller catchers, like Joe Mauer, were better at framing pitches that were high in the strike zone.  And further, shorter catchers, like Jonathan Lucroy, were better at framing pitches low in the strike zone.  

It's not a huge effect: the correlation between high strike calls and catcher height was 0.35.  For low strike calls, it was -0.12, which is probably not significant.  But it's a neat idea, and at least for tall catchers, it might be a thing.  If you have a pitcher who lives up in the strike zone, all else being equal, you're best off choosing a taller catcher than a shorter catcher (assuming otherwise equal framing skill).  Fun tidbit!

Curveballs: illusions and reality

A few years ago, I got to teach a fun freshman seminar course that I called The Science of Baseball.  We covered baseball from a number of scientific approaches: physics, biology (PED's!), psychology, economics, etc.  It was a blast...someday I need to do that again.  I still have the reading list, though it's a bit outdated.

In any case, Michael Maffie had a nice piece today at Redleg Nation highlighting something that is right up that course's alley.  He highlights a PLOS One study that noted an optical illusion that could affect batters' ability to track curveballs.  In the comments, there was also some discussion about why breaking pitches curve.

I wrote this in response, built largely on what I gleaned from Robert Adair's The Physics of Baseball.

Cool stuff. I remember seeing that PLOS One study when it was published, but I’d completely forgotten about it. :)

A few thoughts:
* I think sliders are very interesting in light of this. Unlike the fastball and curve, which will flash as the ball tumbles through space, slider spins are such that the stitches do not “tumble.” Rather, batters see a white “dot” created by the spin as the slider spins on its axis. Therefore, maybe this is yet another difference between what a batter perceives when a pitcher throws a slider vs. other pitches? 

* I have a very basic understanding of curveball (and fastball) physics. But this is the basic breakdown, I think, based on what I read in Adair’s Physics of Baseball. Hopefully it’s correct. 

- The stitches cause the surface of the ball to be “rough.” Rough surfaces create the opportunity for the ball to collect a layer of air around it as it travels at high velocities. This protective layer of air helps to allow for much lower drag than a smooth ball would experience. that effect bottoms out at ~80 mph and then increases again as you increase in velocity. At velocities relevant to baseball, therefore, higher velocity = higher drag = more force applied to baseball. 

- The fact that a curve ball is spinning results in different effective velocities on the top and bottom of the ball. The top part of the ball in a curveball is spinning “into” the wind, and thus has higher velocity, and thus more drag. The bottom part of the baseball, spinning “away” from the wind, experiences less drag. This difference in drag results in more force (called the magnus force) on the top compared to the bottom of the baseball. Therefore, curveballs drop at a (slightly) faster rate than expected by gravity. 

- Fastballs work the opposite way. A four-seam fastball rotates such that the the seams on the bottom of the baseball are rotating into the “wind,” such that the bottom of the baseball experiences greater magnus force than the top of the baseball. As a result, four-seam fastballs (at least) fall less than would be expected by gravity. They still definitely fall (there is no true “rising” fastball), but since we “expect” a normal ballistic path (more or less), they look like they’re defying gravity. 

You can see this deflection on pitchf/x graphs. Brooks Baseball isn’t working for me right now(?!), but if you go here....
Look at the Vertical vs. Horizontal movement graph. Fastballs show up as having “positive” vertical movement, whereas curveballs have “negative” vertical movement. Zero, in that case, would be no deflection from what you’d expect by gravity alone.
Fun stuff!!
-j

The New Manny Parra

Back in December, Redleg Nation released a fantastic interview with Mack Jenkins, the Reds' Bullpen Coach last season.  It's a great listen--Jenkins really impressed me, and provided a great, practical insight into what it is to be a pitching coach.  I listened to it at the time, but never had a chance to follow up on it.

One of the things I found most interesting was the discussion of what happened with Manny Parra last season.  He described Bryan Price giving him a project to look into Manny Parra's pitches and mechanics, and try to find a way to help him improve.  One of the things he reported back was that Parra's curveball was really inconsistent, and that really hurt his performance.  So, they encouraged him to drop it in favor of a slider.

Not that I doubted it, but I wanted to look at his pitchf/x profiles.  Here are Parra's 2009-2012 pitches:

You can see him grade out as having a fastball, a split finger, and that curveball.  Note that each dot above is an individual month during that time period, not an individual pitch.

Here are his 2013 pitches:

And there's the slider!  Note that the y-axis changed here.  The curveball came in around 77mph and had a spin axis over 300 degrees, whereas the new slider comes in at 83 or so with a sub-300 degree spin, so it's clearly a new pitch.  Just to show this more clearly, here are his 2012-2013 pitches:

All of the sliders were thrown in 2013, and all of the curveballs were thrown in 2012.

Another interesting thing: it wasn't an occasional-use pitch for him.  In 2013, he threw his slider 41% of the time, compared to just 18% for his curve in 2012.  

Looking at his stats:

The biggest change of substance in his record looks to be a dramatic improvement in his walk rate.  He also posted a career-best BABIP, though it was still above league-average (last year that was 0.297).  I think that both of those things could potentially be attributed to swapping his curve for a controllable, effective slider.  Now he has a pitch that he can throw for strikes, and can induce strikes (45% of swings at the slider were whiffs last year).  And if hitters are whiffing at the pitch, they're going to be making weaker contact with it when they do strike true.  Finally, if they have to beware of his breaking ball, they can't sit on his fastball and sinker.  

Kudos to Parra, Mark Jenkins, and Bryan Price for figuring this out!  I love seeing pitchers making real, measurable changes in their approach that result in such dramatic performance improvements.  Here's hoping he can do it again this year!