ball four

Evaluating Outfielders’ Defense Using Fieldf/x

While I’m sure that teams have already begun analyzing Fieldf/x data, I wanted to draw up a concept for evaluating outfield defense using Fieldf/x data. The two main defensive responsibilities of an outfielder are preventing runners from advancing on fly balls and converting fly balls into outs. Fieldf/x data can help us determine how well outfielders are accomplishing these objectives by looking at outfielders’ arm strength and the routes that outfielders take to balls.

In order to evaluate routes to the ball, we must first plot the fielder’s path. We must then draw a straight line from the fielder’s original spot to the location where the ball landed or was caught. This is the quickest path to the ball. Below are a couple of images that depict the fielder’s path and the straight line to the ball.

Fielder Route Overview

Fielder's Route Zoom

The amount that the fielder’s path deviates from this straight line will determine the fielder’s route score. This deviation can be measured by the line integral of the arc approximating the fielder’s path. In order to account for the distance from the fielder’s original position and the ball’s ultimate landing location, we must divide the line integral by the magnitude of the straight-line vector between the fielder’s original position and the ball’s ultimate landing location.

Outfielder’s Route (ORt) = ∫∫ 1 dA / √[(a2- a1)+(b2- b1)]2

The route that outfielders’ throws take could serve as a proxy for measuring how good a player is at preventing runners from advancing. A similar approach can be taken here as the one taken in evaluating routes. We can measure the deviation of each throw from a perfect throw and normalize it with the distance of the perfect throw.

In other words, we would take the line integral of the arc approximating the fielder’s throw and divide it by the magnitude of the straight-line vector from the outfielder’s position to the intended target.

Outfielder’s Arm Accuracy (OAA) = ∫∫ 1 dA / √[(a2- a1)+(b2- b1)]2 

Finally, we could index the speed of the outfielders’ throws against the league average speed to get the Outfielder’s Arm Strength (OAS).

Outfielder’s Arm Strength (OAS) = Outfielder’s Throw Speed / League Average Outfielder’s Throw Speed 

These three metrics should give us a more comprehensive look at outfield defense as they evaluate how well outfielders run routes towards fly balls and how accurate and strong their throws are.

2012 Cubs Preview: Starting Rotation [Part III]

Chris Volstad | Can Volstad handle left-handed hitters?

In his career, Volstad has had trouble pitching to left-handed hitters. The trouble primarily comes from Volstad’s inability to keep left-handed hitters from hitting the ball out of the park and taking walks. In 2011, he gave up 2.16 HR/9 and posted a 3.86 BB/9 against lefties. Against righties, Volstad gave up 0.42 HR/9 and posted a 1.56 BB/9. The issue is pretty obvious: if Volstad wants to be a successful starter this year, he’s going to need to find a way to get left-handed hitters out.

While we should always be careful when we’re working with small sample sizes, I looked at Volstad’s spring performances to see if there were any signs of him figuring things out against lefties. Below is a chart comparing Volstad’s career lefty-righty splits against his spring lefty-righty splits.

As we can see, managers seemed to know of Volstad’s weakness and ended up stacking their lineups with left-handed hitters. Surprisingly, Volstad had no issues with the left-handed hitters. He didn’t allow a home run or a walk in the 10 innings that he pitched against lefties. While there are a number of other factors that could be in play here - the quality of the opposing left-handed hitters, small sample size, etc. - these numbers are encouraging. Let’s hope that this change is a result of a change in Volstad’s approach rather than just luck.

The Rest | How much better is our starting pitching depth this year as opposed to last year?

It’s pretty clear that we not only have more starting pitching depth to start off this year, but also a better quality of depth than we did last year. Going into Opening Day last year, we had Casey Coleman and James Russellas our extra starters. This year we have Randy WellsTravis Wood, Casey Coleman, and Rodrigo Lopez.

While I should technically compare the two years based on the six pitchers that I have thus far named, I includedDoug DavisRamon Ortiz, and Rodrigo Lopez - they were all acquired within the first two months of the season - in order to make the analysis a little more worthwhile. Below is a chart with the production of the 2011 extra pitchers followed by a chart of the ZiPS projections for the 2012 extra pitchers.

There are a few points that I would like to discuss: the age of the pitchers, innings pitched per inning, and the actual effectiveness of the two staffs.

In 2011, we only had one true extra starter, (James Russell is clearly not a true starter), below the age of 30: Casey Coleman. The weighted average age of our extra pitchers was 30.3 years. This year, we have three extra starters below the age of 30: Casey Coleman, Travis Wood, and Randy Wells. The weighted average age of our extra pitchers is 28.2 years.

Last year, the extra starters averaged 5.05 innings pitched per game started. This year, the extra starters are projected to average 5.60 innings pitched per game started. While half an inning may not seem like a lot at first sight, let’s put it into perspective. Last year, our extra starters started 49 games; if the starters, on average, could have pitched an additional half inning per start they would have saved our bullpen about 25 innings pitched over the course of the season. Not only is that less wear and tear on the bullpen, but that could also provide the manager with a little more flexibility when it comes to how he uses his bullpen.

Lastly, we look at effectiveness. Last year, the extra starters put up a combined 5.91 ERA/4.90 FIP, which is pretty atrocious. This year, the extra pitchers are projected to put up a combined 4.60 ERA/4.50 FIP. While that isn’t remarkable, it’s certainly a significant improvement over last year’s numbers. Below is a chart summarizing of some of the key comparisons that we’ve looked at.

While we hope that none of these extra starters will have to log more than a few starts here and there, we can be confident that we’ll be much better prepared to deal with any injuries to our starting rotation this year as opposed to last. Not only do we have more quantity, but we also have better quality.

As always, let me know what you guys think. I’ll try and get a preview of the bullpen up by Thursday; if I can’t, look for it later this weekend. If you have any suggestions for questions you’d like me to answer about the bullpen, then please let me know in the comments.

I weighted the ages by innings pitched in order to arrive at a more representative average age of the extra pitchers.

As you probably noticed, ZiPS projections have each of this year’s extra pitchers logging over 130 innings. While that is highly unlikely, their rate statistics are not dependent upon the number of innings pitched, so measures such as strikeout, walk, and homerun rates, as well as ERA and FIP, should be, (in theory), the same if a pitcher pitches 50 innings or 150 innings.

2012 Cubs Preview: Starting Rotation [Part II]

Paul Maholm | Will the Cubs infield defense be good enough to convert Maholm’s ground balls into outs?

In my post about Maholm a few months ago I mentioned my concern with his declining swinging strike rate, and the subsequent increase in his contact rates. Higher contact rates will result in a greater number of balls in play, and will make Maholm’s results even more dependent on his defense.

In that same post, I posted a comment comparing Pittsburgh’s defense versus our defense looking forward. I’ve modified that comment to make it more salient.

Let’s look at the UZRs of the Pirates 2011 infield versus the projected UZRs of the Cubs 2012 infield. I focus on the infield because of Maholm’s high GB%.

1B: LaHair 1.5 UZR | Pirates -7.5 UZR
2B: Barney 6.1 UZR | Pirates -3.4 UZR
SS: Castro -7.7 UZR | Pirates -0.4 UZR
3B: Stewart 0.2 UZR | Pirates 7.7 UZR

Based on last year’s UZRs, (for Barney and Castro), and career average UZRs, (for LaHair at 1B and Stewart at 3B), the potential 2012 Cubs infield would post a 0.1 UZR, which would be significantly better than the 2011 Cubs, who posted a -15.9 UZR, and slightly better than the 2011 Pirates, who posted a -3.6 UZR.

However, the fact that Pena and the other Cubs 2011 first baseman only compiled a 0.9 UZR last year makes me question my projection for LaHair. Based on what many here on this site have mentioned about how LaHair has fielded first base this spring, I would feel much more comfortable projecting LaHair at a UZR much lower than his career average. Furthermore, LaHair’s fielding issues could negatively affect the rest of the defense. Based on these adjustments, I could see the best case scenario being a UZR closer to the -3.6 UZR of the 2011 Pirates.

If the 2012 Cubs infield defense is on par with the 2011 Pirates infield defense, Maholm’s ERA will be near 4.00, which I would gladly take from our fifth starter.

Ryan Dempster | Was 2011 the beginning of the end for Dempster?

In his four years as a starter for the Cubs, Dempster had his worst ERA in 2011. His 4.80 ERA was almost a full run above his previous high of 3.85. However, as we can see below, his FIP and xFIP were essentially in line with his 2008-2010 average.

When pitcher’s have ERAs that are higher than their FIPs and xFIPs that usually means that one of their “luck” statistics were out of whack. Sure enough, Dempster had a .324 BABIP, well above his the .292 BABIP that he posted between 2008 and 2010.

While I was tempted to chalk up Dempster’s struggles to him being unlucky, I wouldn’t have been doing my due diligence if I had ended here. This is because BABIP is driven by much more than just luck, in fact it’s driven by four factors: team defense, pitcher’s talent level, pitcher’s skill set, and luck. Let’s quickly examine a couple of these factors and how they relate to Dempster’s 2011.

Team Defense

If we look at the following chart, we can see that Dempster benefitted from the Cubs’ 2008 defense, and has been hurt in more recent years by the Cubs’ poor defense.

However, as bad as the Cubs 2011 defense was, it was only slightly worse than the 2010 defense by UZR standards, but Dempster’s BABIP was still 30 points above his previous year BABIP, and over 20 points above the Cubs team average BABIP. While defense has played a part in Dempster’s BABIPs between 2008 and 2011, it doesn’t explain Dempster’s .324 BABIP too well.

Pitcher’s Talent Level

When we’re evaluating major league pitcher’s, the most important variable for this factor is health. Aside from some minor hip and back issues that kept him from making an early July start, Dempster was healthy.

Pitcher’s Skill Set

It has been discovered that pitchers with high strikeout rates tend to generate weaker contact, and thus allow fewer hits on balls in play. Thus, we would expect pitcher’s with higher than average strikeout rates to have lower than average BABIPs. If we look at the past four years, we can see that Dempster’s strikeout rates have remained relatively high. At 8.5 K/9 last year, Dempster’s strikeout rate was well above the league average of 7.1 K/9, which would suggest that Dempster should have had a below average BABIP.


After evaluating the above factors, we’re left with luck, and in this situation luck likely played a large role in Dempster’s .324 BABIP. He didn’t experience any major changes in his team’s defense or his skill set that could have explained the BABIP change, and unless Dempster was suffering from an undisclosed injury, Dempster likely just suffered from bad luck.

Assuming that I looked over everything correctly, this is really the best answer that we could have hoped for; based on this, I would expect Dempster’s ERA to bounce back below 4.00 this year.

As always, let me know what you guys think. I’ll get to Part III within the next few days. If you have any suggestions for questions you’d like me to answer about the rest of our rotation or bullpen, then please let me know in the comments.

2012 Cubs Preview: Starting Rotation [Part I]

Matt Garza | Has Garza become a more efficient pitcher? Does he throw fewer pitches per inning?

During the Cubs vs. Rockies broadcast, Keith brought up the fact that Garza needs to cut down on his pitches per inning in order to provide more innings for the Cubs. I recalled Garza going deeper in games during the last month of the season, and wanted to see if he had become more efficient near the end of last year.

Here is a graph with Garza’s pitches per inning by start in 2011.

As we can see, there is a slight downward trend in the number of pitches he threw per inning. In his 15 post-All Star Break starts, Garza threw less than 16 pitches per inning in 9 of them. Why is 16 such an important number? Let’s look at Garza’s pitches per inning in his career.

As we can see, Garza has averaged over 16 pitches an inning in each of his four full seasons. The fact that he broke that mark in 60% of his post-All Star break starts is interesting, but not conclusive evidence that he has become a more efficient pitcher. Since 16 pitches is his career average, we would expect Garza to be above that 50% of the time and below that 50% of the time. Looking at his post-All Star break starts, we would expect Garza to be below 16 pitches per inning in 7.5 of his starts and above 16 pitches per inning in 7.5 of his starts. In actuality, Garza was below 16 pitches per inning in 6 of his starts and above it in 9 starts. This isn’t a large enough variation to indicate a change in Garza’s pitch efficiency, but it’s definitely something to keep tabs on as the season gets going.

Jeff Samardzija | Did Samardzija turn the corner in 2011?

Samardzija was very lucky in 2011. He sported a career-best .253 BABIP, (.300 BABIP is league average), career-best 75.0% LOB%, (70% LOB% is league average), and a 5.3% HR/FB rate, (9.5% is league average).

While Samardzija benefitted from good luck in 2011, there are some signs that point to skill-based improvement and not just luck-based improvement. First of all, Samardzija put up his highest strikeout rate of his career, 8.9 K/9, along with his highest swinging strike rate of his career, 9.9%, (8.5% is league average). Furthermore, though he ended the season with a pretty awful 5.11 BB/9, the majority of his control issues occurred early on in the season: in his first 18 appearances, (24.1 IP), Samardzija walked 23 batters. As we can see from the chart below, Samardzija ended up hovering between a 3.0 BB/9 and 4.9 BB/9 for the majority of the rest of the season. If we split the difference, we see that Samardzija’s true talent level is likely closer to 4.0 BB/9 than 5.0 BB/9, which would be good for a strikeout-to-walk ratio greater than 2.

Samardzija’s Pitch f/x data provides us with some interesting information regarding his pitch frequency and effectiveness.

Samardzija threw his changeup half as often in 2011 as he did in 2010. Furthermore, over the past three years, he has been phasing out his curveball, as he threw it only 1.3% of the time last year. He threw fewer changeups and curveballs last year in favor of more fastballs (65.6% in 2010 versus 71.6% in 2011), and sliders, (13.7% in 2010 versus 17.7% in 2011).

Samardzjia’s fastball and slider were his best pitches in 2011. For the fist time in his career, he had a fastball that was above average in effectiveness, (1.43 wFF/C - weighted average of all of his fastballs). Furthermore, his slider, (1.59 wSL/C), and changeup, (.61 wCH/C), both had above average effectiveness levels. While Samardzija had three above average pitches last year, he was primarily a fastball and slider pitcher as these two pitches accounted for over 90% of his pitches in 2011. Starters usually need more than two effective pitches - if Samardzija really wants to start this year, he might need to begin throwing that changeup with more regularity.

Lastly, I looked at some Pitch f/x velocity charts, which plot the velocity of his pitches by appearance.





If we look at Samardzija’s fastball velocity over his major league career, we see that it really picked up this year. In his first three years, Samardzija threw his fastball between 91 and 95 mph. He did the same for about the first 25 appearances of 2011, but then began consistently throwing between 95 and 98 mph for the rest of the season.

Samardzija’s uptick in velocity, change in pitch frequencies, and more effective fastball and slider helped him turn the corner in 2011. It will be interesting to see whether or not he can develop that changeup to the point where he’s comfortable throwing it more often. If he can, Samardzija could finally become a capable major league starter.

As always, let me know what you guys think. I’ll get to Part II within the next week. If you have any suggestions for questions you’d like me to answer about the rest of our rotation or bullpen, then please let me know in the comments.

* Here’s a short primer on pitch values.

Thanks to FanGraphs for Pitch f/x Pitch Values data.

Thanks to Joe Lefkowitz for his Pitch f/x data.

2012 Cubs Preview: Outfield

Right Field: David DeJesus | Is DeJesus our best lead-off option?

According to The Book, the optimal lead-off hitter (i) has a high OBP, (iii) should be one of the team’s three best hitters, and (iii) should have little power. Let’s see if DeJesus fits this mold.

High OBP

DeJesus sports a career .356 OBP - the highest of any current Cubs hitter. According to ZiPS, here are the three highest projected OBPs for the 2012 Cubs.

While DeJesus has a good career OBP, ZiPS projects him to get on base at a lower clip than his career level. Regardless, the difference between the top three OBPs is so small that it’s a toss-up.

Should be one of the team’s three best hitters

According to ZiPS here are the five highest projected wOBAs for the 2012 Cubs.

While DeJesus isn’t technically one of the three best hitters on the team, the projections have him right in the thick of things, as he’s only a handful of wOBA points away from the top three.

Little Power

I have ranked the five players whom we have considered in the previous two analyses by their projected ISOs.

DeJesus is projected to have more power than both Castro and Byrd, but significantly less power than Soto and LaHair.

DeJesus’s relative blend of power and patience does not make him our best lead-off option. However, this exercise has revealed who should actually be hitting first: Starlin Castro. He’s projected to have the highest OBP, be one of the three best hitters on the team, and have the lowest ISO in 2012. While many fans would like to see Castro move down in the order, he’ll have to develop a little more power and we’ll have to find a better lead-off hitter than him before he’s moved down. He’s the best lead-off hitter that we have this year.

What does this mean for DeJesus? He’s clearly one of the best OBP threats we have, one of our four best hitters, (with little separating him from the top three), and does not have enough power to bat in the heart of the order. That said, I see him slotting in very well in the #2 spot.

One last thought on our 2012 lineup: below is what I think is our optimal lineup.

1. Starlin Castro

2. David DeJesus

3. Marlon Byrd

4. Bryan LaHair

5. Geovany Soto

6. Alfonso Soriano

7. Ian Stewart

8. Darwin Barney

Center Field: Marlon Byrd | Did the ball to Byrd’s head affect his distance from the plate?

After taking a pitch to his head in Boston, we might expect Byrd to alter his plate approach by taking a step back in the batter’s box to avoid a reoccurrence of that hit by pitch. This would make Byrd more susceptible to off-speed pitches - particularly sliders - away from him. First, let’s take a look at some pictures.

On the left, we have Byrd batting against Houston in 2010. On the right, we have Byrd batting against Washington in 2011.

There doesn’t seem to be a visible difference between the two images. It looks like Byrd is as close to the plate post-injury as he was pre-injury.

However, if we look at Pitch f/x evidence, we get a slightly different story.

Byrd swings and misses at outside curveballs and sliders with much more frequency post-injury than he did in 2010. Keep in mind that the post-injury chart includes only three months of data, while the 2010 chart includes a full season’s worth of data; even if it looks like he’s swinging and missing at about the same number of pitches curveballs and sliders post-injury as in 2010, he’s done it in less than half a season’s worth of time. While this could just be the result of a small sample size, it could also be evidence of him standing further away from the plate. If Byrd was standing further away from the plate, he would be more concerned about letting pitches go by for strikes on the outside corner, thus expanding the outside portion of his strike zone in the process.

Left Field: Alfonso Soriano | Is Soriano the most overpaid player in baseball? Putting the money aside, is he even our best option in left field?

I cheated here and chose two questions, primarily because they were both easy to answer. I’ll address the overpaid question first.

Here is a list of the 20 highest paid players in 2011 ranked by the amount that they were overpaid or underpaid.

As we can clearly see, Soriano wasn’t the most overpaid player in 2011. In fact he wasn’t even the most overpaid player on the 2011 Cubs - that honor goes to Carlos Zambrano. While $13.15 million is nothing to sneeze at, at least it wasn’t the worst contract out there, (at least in 2011). Regardless, the end of the 2014 season can’t come soon enough.

Now let’s see if Soriano should even be one of our three outfielders. Below are 2012 ZiPS projections for our outfielders:

Until Brett Jackson is promoted, it looks like Soriano is far and away our best option in left. However once Jackson’s called up, things get a little murkier. Soriano and Byrd are essentially projected to provide the same offensive performance in 2012. Assuming that Byrd wouldn’t be opposed to moving to left field, Sveum could platoon the two in left. Ideally Sveum would play Byrd against righties, (105 wRC+ over the past four years), and Soriano against lefties, (124 wRC+ over the past four years), to maximize the offensive output of left field. It looks like Sveum will be allowed to pencil in the best lineup regardless of the amount of money that is sitting on the bench on any given day. If this in fact ends up being the case, Soriano could find himself on the bench for a large portion of the 2012 season.

As always, let me know what you guys think. Again, if you have any suggestions for questions you’d like me to answer about players I have yet to look at, please let me know in the comments.

Thanks to Dan Szymbroski for his ZiPS projections.

Thanks to Joe Lefkowitz for his Pitch F/X data.