Does the World Baseball Classic impact MLB performance?

Spring training means nothing, and that depresses me. It feels like baseball is back, but then I realize it’s not really back, and I have to fill out March Madness brackets that never come true to waste my time until early April.

Well, hardcore baseball fans do have something to look forward to every four years (even though it was three between the 2006 and 2009 games). This is the World Baseball Classic, and the 2017 installment begins this Monday. The United States, which has never placed higher than fourth, has its best roster to date, despite the fact that it’s missing some of the country’s best stars.

Regardless, a strong showing from the U.S. squad in the games could help the WBC’s ratings in the states, something that has been a concern to Major League Baseball for the past three games. The first pitch of the tournament will be thrown on Mar. 6, and many big-leaguers are representing their countries for the next few weeks.

Yes, these Major League Baseball players are giving up a couple of weeks of their Spring Training time in order to participate in higher-stakes play in different parts of the world. This leads some observers to argue the WBC can harm players who participate. One such observer, Orioles manager Buck Showalter, told the Baltimore Sun this past week that he believes the WBC disrupts an internal clock players have:

“There are some unique challenges this spring that we don't normally have,” Showalter said. “I understand the return we're trying to get. The biggest thing probably is the clock that changes. Players are creatures of habit and routine, and every team is completely different because they're going to come back from this, and we're going to have to slow down and start the clock again.”

Today, I tried to find out whether that was truly the case.

Before I go into the results, I must share the process I took.

First, I looked at the rosters of all 16 teams of the three WBCs to date — 2006, 2009 and 2013. I found all the players who were currently playing in the major leagues, and then I removed the players who did not amass at least 30 innings pitched or 300 plate appearances in the year prior to and the year of the WBC. For instance, if a 2013 WBC participant pitched 45 innings in 2012 but just 17 in 2013, I omitted him from the data.

I did this because I wanted to specifically find the impact on Major League regulars, not the Quad-A player who’s on the bus back-and-forth from Triple-A throughout the season. While this does leave the process vulnerable to survivorship bias — since a player who gets hurt as the result of the WBC’s workload won’t be included — the samples of 300 PA and 30 IP will incorporate platoon players and relievers, as well as most injury cases. Other than that, though, those numbers were completely arbitrary.

2006 World Baseball Classic

Participants in the 2006 WBC found their net fWAR from 2005 to 2006 decrease by 0.2 wins. Pitchers found themselves almost 0.3 wins worse, while hitters saw a loss of only 0.1 win in their WAR. Overall, as the chart shows, 54 players saw their WAR decrease from 2005 to 2006 and 48 saw their WAR increase.

2009 World Baseball Classic

The most drastic losses of the three WBCs took place in 2009, with players losing an average of almost 0.4 wins on their WAR from 2008 to 2009. Interestingly enough, position players saw a larger drop in WAR than their pitcher counterparts in 2009, with hitters losing around 0.43 wins and pitchers dropping 0.32. Of participants in this WBC, just 35 saw an increase in their year-to-year WAR, with 56 seeing some sort of decrease.

2013 World Baseball Classic

Lastly, here’s the data from the 2013 WBC. After this edition, participants saw their WARs drop about an average of 0.3 wins. Like 2009, pitchers once again saw their WARs drop the most, at about an average of -0.31. Position players here saw an average drop of about -0.27 wins. And 50 players saw a negative year-to-year WAR, with just 31 seeing a positive.

Putting it all together

For pitchers, the WBC does have rules regarding the amount of pitches they can throw with certain amounts of rest. However, the workload could have an impact on every single player who participates. The wear-and-tear of the tournament (the two championship teams play eight full games, in addition to travel time) may have some sort of effect on the players. Of the 274 players that saw their WAR fluctuate from the year before the classic to the year of, 160 (58.4 percent) players saw a negative change and lost an average of -0.3 wins.

Of course, when we’re working with such small decimals in fWAR change — which FanGraphs itself notes is not a perfect formula — it is hard to really determine whether the World Baseball Classic is what is impacting the group of players that I highlighted. (Or, if it is, if it is doing so alone.) And, yes, the sample size is still small, although under the standards I created, it was the largest I was able to work with.

I’m not able to point at the World Baseball Classic and claim that it is the sole reason for this change. With that said, a negative impact on the players is still something to consider for future versions (should they occur). So when the WBC begins Monday, with the likes of Buster Posey, Nolan Arenado, Paul Goldschmidt, and Miguel Cabrera taking part, I will not only be enjoying the presence of meaningful baseball but also considering what it does to these players in the 2017 season.

For full WBC data, player-by-player, visit this link.