Tactically spelled out across a double-word scoring tile, “groutier” – from “grouty”, meaning cross, sulky or surly – earned Nigel Richards 68 points, $8,000 (£6,200) and the right to call himself the greatest ever player of competitive Scrabble.

The 51-year-old Malaysian-based New Zealander took his fourth English Scrabble world title in 11 years after beating the American Jesse Day 3-1. Richards is the only player to have won the title more than once, and he also took the French Scrabble title for the second time earlier this year.

The victory came after a marathon 36 games in a week of knockouts involving 116 players representing 25 countries. The final was fought at in Shepherd’s Bush, west London, to mark the board game’s 70th anniversary.

The youngest player to compete was nine-year old Muhammad Misbah Ur Rehman from Pakistan. Brett Smitheram, the 2016 champion, was the highest ranking Briton, finishing fourth.

#BREAKING: Nigel Richards is the 2018 World Champion! #WSC2018 ends with a 3-1 win over Jesse Day in London after five days of tournament play. — WESPA (@WorldScrabble) October 28, 2018

After defeating Day by 575 to 452, Richards, who described his opponent as “impressive”, posed for photographs with the winning board and the glass trophy.

“I am absolutely thrilled,” he said, barely cracking a smile. Day, who dwarfed his much smaller runners-up trophy at the photocall, nevertheless managed a much broader grin.

Scrabble fans took photographs as Richards and Day faced off in a best-of-five final, which organisers described as “nail-biting”.

Day said: “Nigel has an extraordinary vocabulary, the best in the world. I was pretty impressed by his play of ‘zonular’ for 100 at the start of a game. It put him at a major advantage in round two.”

Among other high-scoring words in the final were “maledict”, meaning to “utter a curse against”, played by Day for 95 points in the fourth round, and “phenolic”, for 84 points, meaning “a synthetic resin”, played by Richards in round two.

The precursor to Scrabble was invented in 1938 by Alfred Mosher Butts, a US architect, who originally marketed it as Criss-Crosswords. Ten years later, an original owner of Criss-Crosswords, James Brunot, bought the rights to the game, slightly changed the rules and renamed it Scrabble.