A Trend Towards Three Outcomes Baseball
Post date: Sep 14, 2017 10:55:48 PM
Baseball analyst Dave Cameron took note of the three outcomes trend in early April, only one week into the new season.
Cameron goes on to predict a record year for the three true outcomes in 2017. He was right.
Figure 1. Changes in three outcomes per plate appearance over time
Figure 1 looks at the average rate of the three outcomes by player for each season since 1913. The top blue line looks at the proportion of plate appearances that have resulted in either a home run, strike out or walk across seasons. I got here pretty easily: For each player with at least 170 plate appearances in a season, I added their home runs, strikeouts and walks in a season and divided that by the number of plate appearances. This approach is typical among baseball analysts, providing the proportion of three outcomes plate appearances for each player. Then for each season I found the average proportion of three outcomes plate appearances. I also followed this procedure for home runs, strikeouts and walks separately.
The trend of the that blue line is clear: there has been a steady trend of increasing rates of three outcomes starting around 1920, dropping off a bit in the 70s, and continuing on through 2017. There has been a spike in recent years, and the 2017 average of 33% three outcomes is clearly the highest proportion since 1913.
It is interesting to look at each outcome separately as well. The tremendous growth in strikeout rates is clearly a big part of this story. Average walk rates have consistently hovered around 8 or 9 percent of plate appearances after peaking just over 10% in 1948. Home run rates are increasing, but home runs are still rare compared to other outcomes. Through the 1940s average home run rates per player averaged around 1% of plate appearances. They jumped to around 2% in the 1950s, and stayed pretty consistent until the mid 1990s. Since then they have been increasing, and peaked in 2017 with an average of 3% of plate appearances.
A Steady Slog toward Three Outcomes Baseball
Dave Cameron’s prediction made at the beginning of the 2017 season appears to have borne out. But what does this trend towards three outcomes mean for the game? Perhaps Cameron subtly showed his feelings about it when he titled his essay, “The League’s continuing March towards Three Outcomes Baseball.” A march; a steady march. Looking back at Figure 1 might suggest a steady uphill march towards three outcomes baseball. He could have called it a race towards three outcomes. Or the growing excitement around three outcomes baseball. Even the uphill battle of three outcomes baseball sounds more intriguing than a march.
Is three outcomes baseball more of a slog than it is an exciting new dynamic in the game? There is a concern among some that the three outcomes eliminate some of the most exciting parts of the game. When a batter either hits a home run, takes a walk, or strikes out, the outcome of his plate appearance does not involve the defense of the fielding team. This is because no ball is put in the field of play. Only the batter, pitcher, and catcher are involved. Does this take away from the game? For many, the best parts of baseball take place when the ball is in the field of play:
The triple is often considered the most exciting play in baseball. The ability to get to third base requires a uniquely hit ball and a fast hitter. A fielder has to get to the ball quickly, and make a strong and accurate throw to third base to have a chance at getting the runner out. The third baseman has to make a clean catch and tag the runner who is sliding to beat the tag.
A typical double play requires coordination among three fielders – a catch, a toss, a bag touch, a strong throw and another catch. All that takes place in seconds; started by fielding a ball traveling between 80 and 90 miles an hour off the bat.
Web Gem highlights are full of outfielders making what appear to be impossible catches at full speed while diving and hitting the ground, banging into a wall, or falling over a fence.
For some fans, there is a lot of strategy that happens outside of the three outcomes – bunts, hit and runs, stolen bases.
Do we really want to see these aspects of the game become less common?
This trend towards three outcomes is interesting and raises questions that require a closer look. Many are empirical: Are three outcomes specialists taking over baseball? If not specialists, are all major leaguers increasing their three outcomes rates? Are there particular approaches to hitting that are driving this trend? Underlying these empirical analyses is the bigger question of so what? Should we be concerned about this trend in baseball, and can baseball analysis add to the discussion of the games direction?
Baseball fans love statistics. MLB and amateur fans have been collecting data by the handful for decades now. The data I’m using here come from Fangraphs. Baseball Reference provides similar data, and has been the pioneer in the field for years. MLB is now making unique data available at Baseball Savant. For a baseball fan and a data analyst like me it is hours of fun.
A Trend Towards Three Outcomes Baseball