The Z Files: Fantasy Impact of the WBC

Something I've learned over the years is in order to dole out the best analysis for fantasy purposes, it's imperative to think like a fantasy owner. In fact, the best advice I received upon becoming a fantasy writer was figure out what you'd want to see as a reader and write that. There have been some in-depth studies looking at the impact of the WBC. What I care about is how it affects fantasy-relevant players.

Before becoming a fantasy writer, I was a Chemist. Something that was drilled into our head was that no result was, in fact, a result. That is, if it turns out the outcome of distilling the WBC player pool to those fantasy-worthy mimics that of deeper studies, it wasn't a waste of time.

Let's define a fantasy-worthy player. For batters, I only care about those accruing 300 plate appearances over the course of the season. For pitchers, I want a minimum of 50 innings pitched. Sure, single-league formats require using players below those limits, but I'm not going to design or alter a plan because of a middle reliever or utility infielder.

In addition, I'm not concerned with the 2006 WBC. It was the inaugural tournament and teams learned better ways to approach the 2009 and 2013 versions.

Looking at the cumulative performance of the qualified players is of less interest than simply the percentage of players falling on either side of the particular test. For example, if I was looking at ERA (I'm not), I care more about the percentage of pitchers with a better first half than second half than their aggregate ERA for each half. One outlier either way can flip the results to a misleading result.

Finally, as hinted, differences in surface stats like ERA aren't as actionable as changes in skill. These skills-based metrics will be compared to that of the league. If the league hit more fewer homers over the first half as compared to the second, and so did the WBC pool, it isn't a big deal. Here, we will use the aggregate stats from every hitter garnering at least 150 plate appearances for the half season. The sample is large enough to flesh out outliers in either direction.

2009 World Baseball Classic

Hitters

Here's how the league's numbers compare in 2007 and 2008 to 2009.

2007-08: .330 wOBA, 17.3 K%, .153 ISO
2009: .329 wOBA, 18.0 K%, .155 ISO

Hitters fanned a little more, but production was similar the two seasons before the WBC compared to the season it was played.

Here's the same data for the WBC participants. The numbers indicate the amount of players performing better in each time frame.

2007-08: 19 in wOBA, 28 in K%, 18 in ISO
2009: 40 in wOBA, 31 in K%, 41 in ISO

Small sample size alert, but many hitters had better seasons in 2009 than they did the two previous campaigns.

Did they start hot because of the WBC? Here's the overall first versus second half data for fantasy relevant hitters.

2009 1H: .344 wOBA, 16.6 K%, .167 ISO
2009 2H: .344 wOBA, 17.2 K%, .166 ISO

Interesting that league-wide production was the same in the first and second half. Now the 2009 WBC batters.

2009 1H: 23 in wOBA, 26 in K%, 24 in ISO
2009 2H: 36 in wOBA, 33 in K%, 35 in ISO

Again, small sample, but WBC hitters seemed to start slow then pick it up over the second half, resulting in a better year than the previous couple. If 2013 data piggybacks, dealing for WBC hitters is an intriguing mid-season ploy.

Pitchers

Let's compare the overall pitching numbers from 2007-2008 to 2009.

2007-08: 17.3 K%, 9.1 BB%, 9.9 HR/FB%, 91.0 velo
2009: 18.0 K%, 8.9 BB%, 10.1 HR/FB%, 91.4 velo

If hitting was stagnant, it stands to reason pitching would follow suit. How about the WBC hurlers?

2007-08: 13 in K%, 19 in BB%, 17 in HR/FB%, 18 in velo
2009: 23 in K%, 17 in BB%, 19 in HR/FB%, 18 in velo

Unlike the hitters, there's no evidence pitching in the WBC helped or hurt performance that season.

Overall, hitting numbers were alike in both halves, so it follows pitching would be too. Let's see if WBC pitchers were also consistent from first half to second half.

2009 1H: 13 in K%, 19 in BB%, 17 in HR/FB%, 18 in velo
2009 2H: 23 in K%, 17 in BB%, 19 in HR/FB%, 18 in velo

Other than a few more pitchers increasing their strikeout rate in the second half, the skills are similar.

2013 World Baseball Classic

Hitters

Here's the overall numbers the two seasons before the 2013 WBC compared to that year.

2011-12: .321 wOBA, 19.2 K%, .147 ISO
2013: .319 wOBA, 19.9 K%, .143 ISO

Offense dropped a bit in 2013. Remember, one of the possible findings is hitters have better numbers after playing in the WBC. Thus, since global production dropped, even if only some of the WBC hitters had a better 2013 than 2011-2012, our theory may have traction.

2011-12: 25 in wOBA, 21 in K%, 27 in ISO
2012: 18 in wOBA, 22 in K%, 16 in ISO

Oh well, we tried. Turns out in 2013, more WBC batters performed better in the years leading up to the tournament than they did the season after it. Combining the two sets of data leans towards hitters benefiting from the WBC, but it's not something to leverage. The most apropos conclusion is not to worry about drafting WBC hitters this season.

Let's complete the hitting study by looking at first versus second half in 2013.

2013 1H: .329 wOBA, 18.7 K%, .151 ISO
2013 2H: .327 wOBA, 18.8 K%, .149 ISO

Big-picture, offense tailed off slightly the second half of 2013. Did the WBC hitters dovetail?

2013 1H: 26 in wOBA, 20 in K%, 26 in ISO
2013 2H: 20 in wOBA, 26 in K%, 20 in ISO

Curses, foiled again. Recall, we were hoping WBC hitters improved over the second half like they did in 2009. But, they didn't.

Pitchers

Let's start by looking at 2011-2012 and 2013.

2011-12: 19.2 K%, 8.0 BB%, 8.0 HR/FB%, 87.5 velo
2013: 19.9 K%, 7.9 BB%, 8.2 HR/FB%, 87.7 velo

And now the WBC pitchers.

2011-12: 34 in K%, 19 in BB%, 28 in HR/FB%, 33 in velo
2013: 15 in K%, 30 in BB%, 21 in HR/FB%, 16 in velo

In 2009, pitcher performance was affected by the WBC. However, it appears velocity and whiffs were down for about two-thirds of the hurlers. Homers were also more prevalent in 2013, through walks dropped.

What happened league-wide in 2013 with respect to first and second half?

2013 1H: 19.9 K%, 7.5 BB%, 8.2 HR/FB%, 87.4 velo
2013 2H: 20.0 K%, 7.7 BB%, 7.9 HR/FB%, 87.9 velo

Recall hitting was a little worse over the second half, supported by fewer homers allowed.

Here's the WBC pitcher data.

2013 1H: 25 in K%, 21 in BB%, 17 in HR/FB%, 10 in velo
2013 2H: 19 in K%, 23 in BB%, 27 in HR/FB%, 34 in velo

Keeping in mine that overall, WBC pitchers performed worse in 2013 compared to the previous campaigns, it looks as though they got off to a slow start, then picked things up, especially in velocity. Still, their seasons were more disappointing than the years preceding the WBC. Another small sample size warning, but if 2016 is anything like 2013, dealing for a WBC pitcher off to a slow start could pay dividends.

Player Performance Summary

To be honest, this was a lot of number crunching to come up mostly empty, but keep in mind this is in fact a useful piece of information. That said, there's some indication it may be wise to avoid WBC pitchers based on the 2013 data. This should probably be considered on an individual player basis and only be used to break a tie.

Injuries

This short Associated Press note shows there were fewer players on the disabled list to begin 2009 as compared to previous seasons, debunking the narrative the WBC leads to more injuries. I looked at the data from 2013 and found no additional risk of injury for WBC hitters. This study by Chris Bragg of Fantasy Pros reveals half the WBC pitchers hit the disabled list in 2013, though he reminds us that Jeff Zimmerman discovered that 40 percent of all starting pitchers have a disabled list stint each season, meaning there's just a bit of added risk from working in the WBC. For what it's worth, Chris also looks at pitcher performance, landing on many of the same findings discussed here.

Even though suggesting there's no reason to worry about hitters and cause to only be slightly concerned about pitchers is useful, it lacks punch, so I'll leave you with something you may find counter-intuitive, especially considering the recent injuries to Salvador Perez and Tom Murphy. Here's some data I prepared for the recent First Pitch Forum spring tour put on by Ron Shandler and Baseball HQ. It looks at the percentage of days spent on the disabled list relative to service time accrued, by position.