Tim Beckham, Dylan Moore, the Seattle Mariners, and three-error innings
Inspiration comes from unexpected places. Mine comes from errors.
I first wrote about baseball in March, 2017 at Banished to the Pen, maintaining a publishing rate of about an article per week through the end of June. After that, I became somewhat disenchanted. Constructive feedback is rare around the blogosphere, and frankly I wasn’t sure if my writing was any good. I suppose I’m still unsure! Regrettably, certainty of skill is rare in most human endeavors.
I found my muse again later that summer through a series of events, one of which was the bottom of the first inning of the Mariners-Yankees game on Sunday, August 27, 2017. The Yankees scored six runs on the way to an easy 10-1 victory, but the Seattle defense was the story of the inning. The visitors made five errors, the most by one team in an inning since 1977.
This unimaginable convergence of failure inspired me to write an article in which I calculated the probability of a five error inning. However, I gave only fleeting mention to the fact that shortstop Jean Segura was responsible for three of the errors himself!
Incredible as this was, I filed the article to the back of my memory. I’m proud to say I haven’t lost my writing inspiration since, and the error article was mostly forgotten. However, baseball has way of reminding us of things lost, specifically Tim Beckham and Dylan Moore.
The 2019 Mariners are off to an excellent start this season, but they seem intent on monopolizing three-errors-by-one-player innings. On April 5, Beckham matched Segura with an E6 trio in the first inning. Less than a week earlier, Dylan Moore was booked for E5 three times in the ninth.
The Mariners clearly have a message for me: my business with error probabilities from nearly two years ago remains unfinished.
The probability of three errors by one player in an inning
Baseball players are becoming more sure-handed at an impressive rate. 50 years ago in 1969, they committed 3,430 errors in 34,890 defensive innings. Last year, the total was 2,792 in 43,489 innings. That’s 638 fewer errors despite 8,599 more innings (due to six additional expansion teams).
Here is the rate of team errors per inning by decade:
| Decade | E/Inning |
| 70s | 9.8% |
| 80s | 9.1% |
| 90s | 8.2% |
| 00s | 7.2% |
| 10s | 6.7% |
Clearly, ballplayers are improving dramatically. Whereas teams averaged one error for every 15.6 innings in 2018, it was just 10.2 innings between mistakes in 1969.
However, there are nine defenders on the field in every team defensive inning. Each MLB player had just a 0.71% chance of making an error in any given inning last year. This varies by player and position, of course. Shortstops and third basemen commit many more mistakes than left fielders. The skill of each player is major factor as well. That being said, any given player should average roughly 140 innings between errors, or 15.6 games.
Within the first week of the 2019 season, Tim Beckham and Dylan Moore each booted three plays in one inning. The chances of one player suffering a three-error inning are 0.000036%. This should happen once every 2,754,987 innings for each player, 306,110 innings for each team, and 34,012 games (210 years!) per team. Yet, it just happened to the Mariners twice in five games!
One of the best aspects of baseball is that each day, you can see something you’ve never seen before. However, history does repeat itself eventually, and sometimes that’s even more remarkable.
