Matt Kemp has been struggling this season, and even if you account for the low BABIP (.303) compared to his xBABIP (.335), he is still striking out at a higher rate this season (28.1%) compared to last (22.9%). What has also confounded me is thatm even though he has a higher strikeout rate, he is also setting a career high in walk rate as well (8.1%). Usually, drawing walks and getting struck out are thought of as tradeoffs, opposite ends of the “patience scale.” Last season, Kemp hit .362/.429/.616 against LHP and .278/.329/.453 against RHP, but this season, he is down to .303/.341/.443 against LHP and .240/.306/.445 against RHP. What happened?

There are two questions 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’s swinging strike percentages (swinging strikes per pitch) and contact percentages (contact made per pitch) against all fastballs (four-seamers, two-seamers, cutters, and splitters). Checking to see any differences between 2009 and 2010 should lend some insight into Kemp’s offensive struggles this season.

I ran several regressions to model surfaces of Kemp’s swinging strike percentages and contact percentages as well as his swing zones. First up, let’s take a look at Matt Kemp’s SwStr% against 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. Further examples and explanations of these swing zones can be seen here. What the swing zones tell us here is that Kemp is swinging less at RHP fastballs in 2010, but is whiffing at a much higher rate as well. He is also missing more RHP fastballs down the middle as compared to before.

Let’s check Kemp’s Contact% against RHP fastballs to see if his swinging strikes are affecting his ability to make contact:

The red contour lines are the same as in the previous two graphs. Clearly, Kemp is making a lot less contact off RHP fastballs, and this tells me that he is putting the ball into play less. The previous two show Kemp swinging and missing more, while these two show Kemp making less contact, particularly on high inside fastballs. Let’s take a look at how Kemp has been doing against LHP fastballs, first at his SwStr%:

Here are his swinging strike plots, Kemp has actually started to swing more on LHP fastballs down and out of the zone (the red contour lines dip in 2010), 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. This is particularly concerning when you consider that Kemp’s wFB/C (runs above average per 100 fastballs) was at 1.64 last season, while that number is down to 0.38 this season. A major part of that drop must have to do with Kemp whiffing on fastballs down the middle that he used to hit.

Finally, let’s look at Kemp’s Contact% against LHP fastballs:

Looking at his contact plots, we see similar colors in where he makes the most contact (making contact 80% of pitches in those areas). But we notice a huge shift in where the epicenter of that hotspot is. 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. This is problematic and adds further evidence that Kemp is simply missing fastballs down the middle as well as chasing high fastballs.

In general, what I present here is what Dodgers’ fans already know: Kemp is swinging and missing a lot. But I hope that I was able to demonstrate clearly how Kemp has been struggling against fastballs, showing where he is whiffing on them and where he is making less contact.

An article over at Memories Of Kevin Malone convinced me that perhaps Kemp’s whiffing behavior this season (along with swinging less and drawing more walks) could have been caused by Kemp’s change in swinging mechanics. Finally, if you visit my blog at Think Blue Crew, you can read a longer post about Kemp’s offensive struggles against breaking balls as well.

A variation of this article was originally posted at Think Blue Crew, a blog dedicated to data visualization of baseball, basketball, and football statistics. Check it out for more f/x visualizations like this.

Mark Reynolds is perhaps one of the more interesting power hitters heading into his prime this season. He has led the entire league in strikeouts since 2008, holding the all-time record for most strikeouts in a season with 223 K’s last season.

This year, he leads the league once again in strikeouts, as well as perennial leader in swinging strike percentage. He has whiffed on 17.3% of all pitches this season, second place being Ryan Howard at 14.4%. Interestingly, Reynolds does not actually swing at everything a la Jeff Francoeur (60.7% swing percentage) and is barely in the top 50 in percentage of pitches he swings at with 46.8%. This makes it even more amazing that Reynolds leads the league in strikeouts and swinging strike percentage regularly without even taking that many swings. That’s a lot of whiffing going on, and I do suppose that the rare times he does connect the bat to the ball, he hits it hard.

I wanted to know more about Mark Reynolds’ swinging strike percentages to see how he fares against certain pitch types by handedness. Of the five main pitch types, fastballs, sliders, cutters, curveballs, and changeups, Mark Reynolds has seen cutters less than 200 times since his debut, 139 cutters from right-handed pitchers and 41 cutters from left-handed pitchers. He has seen at least 200 pitches for the other pitch types for right-handed pitchers or left-handed pitchers. Ignoring cutters due to small sample size, I will take a look at Reynolds’ swinging strike percentages against four-seam fastballs, sliders, curveballs, and changeups.

Let’s take a look at Mark Reynolds’ swinging strike percentages against four-seam fastballs split by RHP and LHP (1435 pitches from RHP, 468 pitches from LHP):

Here, it looks like Reynolds falls victim to high fastballs from both right-handers and left-handers. For Reynolds, he whiffs on the outside fastball from LHP stick out as well as the low and inside fastball from RHP.

Here’s a look at Reynolds against sliders (1542 from RHP, 224 from LHP):

This is interesting. Reynolds strikes out far more against right-handed pitchers than against left-handed pitchers, but he tends to swing at (and miss) sliders coming from LHP more than he does from RHP. LHP sliders come low and inside while RHP sliders go low and outside, but even LHP sliders coming in from low and outside are swung at and missed by Reynolds.

Curveballs against Reynolds are a whole different story (567 from RHP, 228 from LHP):

Here, Reynolds clearly struggles at connecting on curveballs from right-handed pitchers, some in the strikezone and most low and outside the strikezone. Curveballs from LHP also get Reynolds to whiff sometimes on the inside part of the plate as well as the lower part.

Finally, here’s a look at Reynolds against changeups, which look like his greatest weakness when it comes to missing pitches (430 from RHP, 338 from LHP):

This is very telling. The splits against changeups are very different, as Reynolds whiffs on over 50% of changeups from right-handers that are located on the edge of the strikezone at the bottom. This is much different from LHP changeups, where any spot doesn’t look to cross over 30% whiff rate, except the lower righthand corner of the zone. What’s also crazy about this is that when you look at Reynolds against changeups in general, he misses at around 20% of nearly all changeups low outside and nearly all areas within the strikezone as well.

From these plots, there are characteristics of Reynolds’ swinging strikes that are similar to conventional thought and common knowledge, such as chasing high fastballs or low breaking balls. But the key to exploiting Reynolds’ weakness at missing the ball when swinging is definitely throwing timely changeups, especially from right-handed pitchers, while it seems that Reynolds is less prone to whiff against LHP curveballs the most.

This article was originally posted at Think Blue Crew, a blog dedicated to data visualization of baseball, basketball, and football statistics. Check it out for more f/x visualizations like this.