Monday, September 20, 2010

Rivera's Cutters @ FanGraphs

I was kindly offered by Dave Cameron to write for FanGraphs after I submitted two articles to their Community Blog. My first post is up, which is a variation of my post on Rivera's cutters based on the count situation a few weeks ago. Check it out!

Saturday, September 4, 2010

Comparing Swing-Happy Contact Zones

Here's a quick look at the contact zones of yesterday's swing-happy hitters, Vladimir Guerrero, Delmon Young, and Jeff Francoeur. Links to plots of their swing zones are right before each picture.

Against fastballs, swing zones vs. contact zones:

Against sliders, swing zones vs. contact zones:

Against curveballs, swing zones vs. contact zones:

And against changeups, swing zones vs. contact zones:

Generally, they look the same as their swing zones, although Francoeur really shouldn't be swinging at so many changeups out of the zone because he doesn't make much contact off of them. Interesting plots, but not necessarily groundbreaking research here. I'm inclined to move on, because it's college football Saturday. Finally.

Friday, September 3, 2010

Comparing Swing-Happy Swing Zones

In the past few years, the batters who have been among the league leaders in Swing% (percentage of pitches swung at) are the same names every year. Since 2008, Vladimir Guerrero has led baseball in Swing% by swinging at 60.4% of all pitches. Delmon Young is second with 60% while Jeff Francoeur is third with 57.90%.

Let's take a look at the 50% swing zones of each of these hitters by pitch type. First up, fastballs:

Vlad swings at more low RHP fastballs than the other two, but Francoeur takes high LHP fastballs, even swinging at fastballs 1.5 feet above the strike zone 50% of the time. Here's sliders:

Vlad takes a hack at a lot of sliders in the dirt from both handed pitchers, and look at Francoeur again. He also really likes to take a chance at those high sliders too. Let's look at curveballs:

For once, Francoeur doesn't look as vulnerable against curveballs (relatively speaking) compared to Delmon Young and Vlad. All three hitters are righthanders, so you can see the same weakness against LHP curveballs coming low and inside. Finally, here's a look at changeups:

All three hitters don't generally swing at inside changeups from LHP, but Francoeur again likes those high changeups. The RHP plot is particularly interesting, as Delmon Young's swing zone goes up and inside, Francouer's swing zone reaches directly up almost two feet above the strikezone, and Vlad swings at a lot of outside changeups from RHP.

Although Vlad swings at the most pitches, both pitches in the strikezone and outside the strikezone, many of Francouer's 50% swing zones are larger than Vlad's. This means Francouer's outside-the-strikezone swings are more widely distributed than Vlad's. For a professional baseball player who thinks high on-base percentages equates passivity, I don't expect Francoeur's habits to change. I mean, he is the guy who was once quoted as saying, "If on-base percentage is so important, then why don't they put it up on the scoreboard?"

Tuesday, August 31, 2010

Matt Kemp's Struggles: Fastballs and Breaking Balls

Kensai over at Memories Of Kevin Malone had a fantastic and exhaustive post on the struggles of Matt Kemp this season. If you haven't read it yet, go read it right now before you continue this post.

A very short Cliff Notes version. Basically, Matt Kemp has been struggling this season, and even if you account for the low BABIP, he is still striking out at a higher rate this season compared to last. What also confounded me that even though he has a higher strikeout rate, he is also setting a career high in walk rate as well. Usually, drawing walks and getting struck out are thought of as tradeoffs, opposite ends of the "patience scale." Kensai also had a meticulous look at the changes in Kemp's swinging mechanics, and he did find a change that hopefully the Dodgers are aware of.

I would like to extend on Kensai's post using PITCHf/x. There are two areas I'd like to investigate: 1) Is Kemp swinging at more strikes in 2010 compared to 2009 and how? and 2) Is Kemp making less contact in 2010 compared to 2009 and how?

To answer these two questions, I'd like to look at Kemp against all fastballs (four-seamers, two-seamers, cutters, and splitters) and against all breaking balls (curveballs, sliders, and changeups). Let's get started with a table of Matt Kemp's plate discipline and swing outcome rates in 2009 vs. that of 2010, broken down between fastballs and breaking balls and by pitcher's handedness:

A lot of numbers in this table. When reading this table, be sure to remind yourself that the blue rows are last year and the white rows are this year. FB stands for fastballs and BB stands for breaking balls. Changes to note between 2009 and 2010: Kemp is swinging less against pitches from RHP but more against pitches from LHP. But in all cases, he is getting more swinging strikes, as well as making less contact, save breaking balls from LHP. This in turn results in less balls in play from Kemp. The last three columns are at a per swing rate (whereas SwStr%, Contact%, and In Play% are per pitch). When Kemp swings, he is whiffing far more in 2009 than in 2010 against BOTH fastballs and breaking balls and RHP and LHP. He is also getting less contact on the ball when he swings in all cases (again, Kemp has performed better in 2010 in In Play% only against breaking balls from lefties).

I have a lot of plots coming up, so I'd like this to be organized and I'll do my best to make concise inferences from the plots. I will be looking at the swinging strike percentages and contact percentages of each combination of fastballs/breaking balls and against righty/lefty. The plots on the left are 2009 and the ones on the right are 2010. There will be four sets of four plots each in the following order:

1) Kemp against RHP fastballs in 2009 vs. 2010 (SwStr% and Contact%)
2) Kemp against LHP fastballs in 2009 vs. 2010 (SwStr% and Contact%)
3) Kemp against RHP breaking balls in 2009 vs. 2010 (SwStr% and Contact%)
4) Kemp against LHP breaking balls in 2009 vs. 2010 (SwStr% and Contact%)

First up is SwStr% and Contact% of Matt Kemp against 1) RHP fastballs:

The red contour lines tell us that Kemp chooses to swing 50% of the time when a ball is thrown within the contour line. This is what I call Kemp's swing zone, so the red circles refer to this. Kemp is swinging at RHP fastballs less in 2010, but is whiffing at a much higher rate as well. He is also making much less contact. The top two graphs show Kemp swinging and missing more, while the bottom two graphs show Kemp making less contact, particularly on high inside fastballs.

Second is SwStr% and Contact% of Kemp against 2) LHP fastballs:

Here in his swinging strike plots, Kemp has actually started to swing more on LHP fastballs down and out of the zone, so his swinging strike rate there is up. But he is also missing a lot more LHP fastballs this year that come down the middle over the plate, ideal pitches for the right-hander to hit out of the park. Looking at his contact plots, we see similar colors in where he makes the most contact, but we see a huge shift. Last year, Kemp made contact off a lot of LHP fastballs down the middle of the plate, but this year, the epicenter of that contact hotspot has shifted a full foot up from the direct middle of the zone to the top of the zone. We can infer that Kemp is making less contact off the sweet spot of his bat, and making more high fastball contact that usually result in pop outs.

What about breaking balls? Third is Kemp's SwStr% and Contact% against 3) RHP breaking balls:

The SwStr% plots don't seem to change much for RHP breaking balls. Kemp is swinging more, however, on inside RHP breaking balls than before. He is clearly making less contact off RHP breaking balls this season compared to last. Last year, it also looks like Kemp made more contact off RHP breaking balls coming to the heart of the plate.

Finally, let's look at the fourth and final set of plots of Kemp's SwStr% and Contact% against 4) LHP breaking balls:

These show Kemp swinging at LHP breaking balls in the strikezone in 2009, but low and inside out of the zone in 2010 in his swing zones. As a result of chasing inside breaking balls, Kemp's SwStr% in 2010 in that lower inside corner has increased dramatically. This also shows in his Contact% plots, as the center of his contact hotspot has also shifted from the very middle of the zone toward the lower inside corner of the zone.

There's a lot of information in the previous 16(!) plots, but here are the Cliff Notes version of what I found about Matt Kemp this season compared to last season:

1) Swinging at less pitches (more walks), but whiffing more on hittable pitches (more K's)
2) Making less contact, but when he does make contact, he also puts the ball in play less
3) Swinging at (and missing) more high fastballs from RHP, resulting in less contact
4) Whiffing on LHP fastballs down the middle of the plate, making more contact on high LHP fastballs and less on down the middle LHP fastballs
5) Swinging at more inside RHP breaking balls and making less contact down the middle
6) Chasing low inside LHP breaking balls more, whiffing a LOT more, and making less contact down the middle

In general, what I present here is what we already know: Kemp is swinging and missing a lot more. But I hope that I was able to demonstrate clearly that Kemp is struggling against both fastballs and breaking balls, and I have shown where he is whiffing on them and where he is making less contact. Whereas Kensai looked at the "why," I'd like to say that I've taken an indepth look at the "how."

There could be plenty of reasons why Matt Kemp's whiffing behavior is so widespread, and this bolsters my belief that Kensai at Memories Of Kevin Malone is on to something with his post on the difference in Kemp's swinging mechanics. It's possible that Kemp started chasing inside sliders, high fastballs, and missing vulnerable pitches that he used to crush for independent reasons all at the same time, but I'm inclined to believe that a difference in mechanics (read Don Mattingly: and approach) is more likely to cause all of this simultaneously. And perhaps there is such a thing as being "too patient."

To evaluate if Kemp has changed his approach, I'd like to look at how Kemp's swinging behavior and outcomes have changed from last year based on count situation. Next time, I'll take a look at Kemp's tendencies and results on the first pitch, when the opposing pitcher is behind in the count (more balls), and when he's ahead in the count (more strikes).

Monday, August 30, 2010

Rivera's Cutters Working the Count

I've talked about Mariano Rivera and his cutter in the past, but it's always interesting to analyze what I consider to be the greatest pitch in the game. I don't believe that there is any other pitch in the game right now that can be used so exclusively yet so dominantly the way that Rivera uses his cutter.

We know that Rivera has pinpoint control and likes to work the outer and inner edges of the strikezone against both right-handed batters and left-handed batters. We also know that Rivera is great at working the count, rarely getting to 3 balls in a count. Combining both of these ideas, can we figure out how Rivera works the count based on the locations of his cutters?

To do this, let's first look at Rivera's cutters by each count since 2007:

0-0: 218 to RHH, 343 to LHH
0-1: 105 to RHH, 188 to LHH
0-2: 57 to RHH, 42 to LHH
1-0: 80 to RHH, 101 to LHH
1-1: 86 to RHH, 108 to LHH

1-2: 60 to RHH, 55 to LHH

2-0: 24 to RHH, 28 to LHH

2-1: 41 to RHH, 37 to LHH

2-2: 47 to RHH, 53 to LHH

3-0: 2 to RHH, 4 to LHH

3-1: 4 to RHH, 4 to LHH

3-2: 15 to RHH, 19 to LHH

Note that these are cutters used in different pitch counts, not total pitches. Rivera does occasionally use two-seam and four-seam fastballs, and he has used traditional fastballs 16.2% of the time this season so far. However, a quick glance at the above list shows us that Rivera rarely falls behind in the count, or rarely uses his cutter when he has three balls. To analyze how Rivera works the strikezone based on the count, it wouldn't be sensible to do a 12-count plot of Rivera's cutters, as he's only thrown the cutter twice to RHH on 3-0 counts since 2007. Instead, let's combine the counts to different situations to see how Rivera locates his cutters as a result:

Count Situation (Not including full count)
On first pitch: 218 to RHH, 343 to LHH

Behind in the count: 151 to RHH, 174 to LHH

Ahead in the count: 222 to RHH, 285 to LHH
With two strikes: 164 to RHH, 150 to LHH

These sample sizes are much better for our plots and should allow us to accurately see how Rivera's cutters are located in different count situations. Let's take a first crack at Rivera's cutters against right-handed hitters on the first pitch and behind in the count along with the batter's swing zones and contact zones:

On Rivera's first pitch of the at-bat, he likes to throw a strike right away, hitting the outer edge of the zone against right-handed hitters, sometimes outside the zone. Hitters have a low contact rate on the first pitch, and when they do, they are better at making contact when Rivera's cutter is up in the zone. When Rivera is behind in the count, he still likes to get the outside edge of the strikezone, but this time looks to throw a pitch in the zone most of the time. Here, hitters make more contact off of where Rivera tends to throw, where the 50% swing and contact zones both encompass Rivera's hotspot. Note that there are shades of yellow on the inner parts of the zone as well, showing that Rivera does throw inside occasionally when he's behind in the count.

Let's look at the same count situations against left-handed hitters instead:

The first pitch to left-handed hitters is approximately the same location as against right-handed hitters, except Rivera locates up and inside in addition to middle inside. LHH have a much smaller swing zone on the first pitch compared to RHH. However, when they do swing, it is usually where Rivera locates his cutter most frequently. This is to say that Rivera's first pitch to LHH is likely to get swung at if it's placed in his hotspot. LHH also have a larger contact zone than RHH and it's located right in that hotspot, which means LHH make contact on the first pitch more often than RHH. Looking at cutters behind in the count to LHH, Rivera still likes that right edge, but locates to the left (outer edge for LHH) more often than to RHH (inner edge). He also goes inside and out of the zone on LHH in this situation more than he does going outside out of the zone to RHH.

What about his cutters to right-handed hitters ahead in the count and with two strikes? Let's take a look:

Here, Rivera goes outside the zone to RHH more often when he has the upper hand. He also locates inside to RHH sometimes too, but the epicenters of his main hotspot shifts to the right outside the zone when he's ahead in the count or with two strikes compared to when he's behind the count. It also seems as if batters swing more freely, swing zones that encompass much of the strikezone and outside as well.

Let's see if Rivera works left-handed hitters when he's ahead in the count the same way he works right-handed hitters:

Here's something different. Just as Rivera throws his cutters outside to LHH more often than inside to RHH when behind in the count, here we can see hotspots emerging on the left outer edge to LHH. When he's ahead in the count, Rivera works either edge, but goes inside and out of the zone quite often (Rivera's cutter moves in on LHH and away from RHH). On two strikes, it's pretty much anyone's guess whether Rivera wants to come outside and then barely hit the outer zone, or come into the zone and just hit the inside of the zone. The best bet for left-handers is to expect the outside cutter, as this count situation yields cutters in this location more than in other situations. Looking at the swing zones, LHH are pretty much swinging anywhere Rivera throws his cutter.

Finally, let's look at a table of different pitch outcomes and batter reactions based on the count situations we looked at above:

These are percentages of total pitches in those count situations, except for Whiff%. The distinction between SwStr% and Whiff% is that SwStr% is a % of total pitches while Whiff% is a % of total pitches swung at.

On the first pitch, RHH and LHH both swing less than 40% of the time, but LHH are definitely more successful at making contact and putting the ball in play. RHH whiff more in most count situations, but Rivera is able to get LHH to whiff more than RHH on two strikes. RHH put the ball in play 40% of the time when Rivera is behind in the count, but only 28.4% when ahead in the count. LHH put the ball in play about 35% of the time whether or not they are behind or ahead in the count.

To recap(itulate), it would appear that RHH are especially vulnerable on the first pitch, whiffing 28% of the time when they swing. RHH would hope to be behind in the count and expect a cutter inside the zone for their best chance of putting the ball in play. Otherwise, Rivera will paint the outer edge if he is ahead, pitching to the black, a difficult pitch to hit to say the least. For LHH, who make more contact off the right-handed Rivera than RHH, Rivera counters by working both edges of the zone. LHH still get whiff rates as high as 19.4%, and especially don't want to let Rivera get ahead in the count, as he will work either the outside edge or the inside edge.

Just looking at traditional statistics will appropriately show how dominant Rivera has been in his career, with a 2.21 ERA, 1.00 WHIP, .209 opponent's BA, and 1044 strikeouts in 1137+ innings. The plots and analysis above shows how he has achieved such success: by living on the black against both right-handed and left-handed hitters, and being able to consistently hit his various spots so that he gets hitters to swing at difficult pitches no matter the count.