Graham Teams With Math Department For Water Polo Stat Analysis

by Jennifer Langham

A math professor and athletics coach at University of the Pacific have teamed up to debunk previously unquestioned ideas about winning techniques in water polo.

Their findings, published in the current issue of the Journal of Quantitative Analysis in Sports, helped guide the Pacific men's water polo team to the national finals last year and garnered a Coach of the Year Award from the Association of Collegiate Water Polo Coaches.

John Mayberry, assistant professor of mathematics at Pacific, and James Graham, the 2013 Coach of the Year, began their research two years ago as part of consulting work for Team USA Water Polo, for whom they continue to provide statistical analysis.

Graham said that reading the book "Moneyball," about the use of statistical analysis in baseball, inspired him to examine mathematically which offensive tactics were most effective in water polo.

While Graham has a bachelor's degree in math that allowed him to start looking at patterns within the game, his collaboration with Mayberry—recommended by a water polo player—helped him make definitive statistical statements.

Mayberry had never watched a water polo game before starting the project, but said that a childhood obsession with baseball statistics earned him the nickname "Stats" from his grandfather.

"While water polo was a completely new application for me, connecting mathematics to real-world objectives has always been one of my goals as a mathematician," Mayberry said.

What they found changed the way Graham coached: The most effective tactics were not the ones usually considered to be best in the sport. They found, for example, that power play conversion rate is the greatest predictor of wins.

They report these and other findings in their paper, "Measures of Tactical Efficiency in Water Polo," published in the quarterly journal.

Graham coached the Pacific men's water polo team to the national championship game last year, competing against USC and finishing as runner-up in double overtime. In addition to the national coaching honor for Graham, the Association of Collegiate Water Polo Coaches awarded the team five All-American awards, the most in Pacific water polo history, and named student-athlete Balazs Erdelyi the National Player of the Year.

Graham gives much of the credit to math. "Without a doubt, one of the factors in the success of the Pacific water polo team this past year was the statistical information we found from our analysis," he said.

Both Graham and Mayberry said that they have many more areas of research to explore – work that will, in Mayberry's words, "keep us writing papers for years to come." Graham has an even larger vision: "I believe we have the opportunity to change the sport of water polo," he said.