Mostly Useless Information About the World Series In the Wild Card Era

We could easily call my decision to publish an article with playoff predictions using a brand-new theory about previous success predicting future success ballsy (or stupid). To summarize, research by Rosenqvist and Skans (2015) [1] showed that golfers who barely qualified for a golf tournament would go on to have more success in future tournaments than golfers who barely missed the cut in the same tournament. Seemingly accidental success created confidence, which led to more success in the future. So, using this logic, I wanted to see if this same phenomenon occurred at the team, rather than the individual level. The attempt was to predict all divisional victors from this year’s 2015 MLB playoffs using previous playoff experience and success as the predictor. As it turns out, the teams with more experience/success were only 1 for 4 in the first round of the playoffs.

This time, instead of making predictions, I did the smart thing and looked at previous trends. Instead of using the first round of the playoffs (which arguably is more erratic given that it’s only a five-game series), I focused solely on the World Series. I totaled all the previous playoff experience, age, and WAR for every player on each 25-man World Series team roster in the Wild Card Era (1995 – 2015, n = 42 teams).

WAR doesn’t predict the winner of the World Series

Is this old news? I don’t know. Tallying up a team’s WAR correlates with the actual number of wins that team will have by the end of the regular season (somewhere around r = .82 last time I checked), but it doesn’t correlate with the victor of the World Series. In fact, 13 out of the last 21 (62%) World Series victors had average WARs lower than their opponent’s.

Differences in experience at the team level relate to the duration of the World Series

The difference in previous playoff experience between the two World Series teams is a good predictor of the number of World Series games that will be played in a series. Specifically, at the team level, the greater the difference in the average previous playoff series won (r = -.45, p < .05, n =21), the average number of World Series appearances (r= -.45, p < .05, n =21), and the average number of World Series titles (r = -.46, p < .05, n =21) between the two teams, the less World Series games played that year. You’re saying, “yeah but what about the 2014 World Series that went 7 games when the seasoned Giants played the inexperienced Royals?” It’s just a trend, not a guarantee.

Other tidbits

  • The higher the average of previous World Series appearances across both World Series teams, the higher number of television viewers (r = .45, p < .05).
  • The World Series victor with the highest average WAR per player was the 1998 Yankees (m = 2.57); the lowest WAR was the 2006 Cardinals (m = 1.26).
  • Oldest World Series victors were the 2000 Yankees (m = 30.7); youngest were the 2002 Angels (m = 27.4).
  • Most experienced victor was also the 2000 Yankees (96% of the team had previous playoff experience), and least experienced were the 2002 Angels (0%).

More needs to be understood about this theory

There was however, no relationship between previous playoff experience and that year’s World Series outcome. In terms of playoff experience, the results from Rosenqvist and Skans could not be replicated in this setting. Baseball isn’t golf, and baseball isn’t an individual sport, it’s a team sport. Perhaps the average and/or aggregate levels of experience within a team might manifest differently than for an individual. So, too, are there other ways to operationalize this hypothesis of previous experience/success, so I wouldn’t write this off as a done deal. We’re still a long ways away from determining how and if this theory occurs within the context of baseball – more research into the theoretical underpinnings is always the answer.

Back to the drawing board.

[1] Rosenqvist, O. & Skans O.N. (2015). Confidence enhanced performance? – The causal effects of success on future performance in professional golf tournaments. Journal of Economic Behavior & Organization, 117, 281-295.

PhD in Applied Research Methodology. Proponent of psychometrics in sports. More work at

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