Sir David Butler, the father of modern election science whose career spanned more than 70 years, has died at the aged of 98. Butler’s friend and biographer, the journalist Michael Crick, paid tribute to him as the “father of psephology” – a word that Butler promoted early in his career to describe “the new study of election science based on the Greek word psephos for pebble which the ancient Greeks used to vote in elections”. “For decades Butler was the foremost psephologist in Britain and around the world,” Crick said. Butler himself once described the term as an “awful, silly, academic joke” that “hangs like an albatross around my neck”. Born on 17 October 1924, Butler studied philosophy, politics and economics at New College, Oxford. His studies were interrupted when he was commissioned as a lieutenant to serve in the second world war. As an undergraduate, Butler adapted a forgotten Edwardian equation, “the cube rule”, for his work on elections. He found he was able to estimate the total number of seats won from the share of the vote polled. It enabled him to forecast the seats likely to be won by the two major parties on the basis of opinion polls. “For the 1950 election, aged just 25, he was the in-house analyst on the BBC’s first ever TV election results programme, a job he retained until the 1979 election,” Crick said. Butler was known for developing the concept of swing – the percentage shift of votes from one party to another between elections. In 1955, he introduced the Swingometer to the BBC’s election night broadcast. It took a more prominent position in the BBC’s 1959 election broadcast and has become a staple of election coverage all over the world. In the biography Sultan of Swing, Michael Crick writes that Butler “didn’t confine himself to an audience of academic colleagues … but was determined to make elections understandable for a mass audience”. Tributes were paid by those who followed in his footsteps. Robert Ford, professor of politics at the University of Manchester, called Butler a “giant of political research”. Anthony Wells, head of European political and social research at YouGov UK, said talking to David Butler was like “a mathematician getting to sit and talk to Archimedes, or a physicist getting to meet Newton”. The BBC’s Nick Robinson described Butler as “the grand daddy of all election poll watchers, analysts, academics and pundits”. Butler’s innovations were recognised early, when at the age of 25 as a research student at Nuffield College, Oxford, he was asked to contribute to the first ever televised election results programme on the BBC. While working there, he was called away to the home of Winston Churchill, then leader of the opposition, who had read an article Butler had written in the Economist and wanted to quiz the young academic on his chances of returning to Downing Street. “They ate dinner together, and were alone for almost the entire evening. They also listened to the radio election broadcast being given that night … and Butler was asked for his verdict,” Crick writes in the biography. Churchill would go on to lose the election. Speaking to the BBC in 2017, Butler said he was glad he wasn’t writing about that year’s general election that would see the Conservatives under Theresa May lose their majority as support for Labour under Jeremy Corbyn grew, defying early polls. He did however open a Twitter account to offer his thoughts on that year’s election. “It’s wonderful to rediscover one is never too old to learn,” he wrote of his foray into social media. As the dust settled on the 2017 vote, Butler tweeted: “Learning to tweet at 92 has been fun. But my musings should now be confined to elections, so I am signing off … until next year?”