The appointment of Sumi as the head of the M1 project was one of a number of organisational changes Yamaha made in the wake of a disappointing 2018 campaign.
These were followed by an improved 2019 season in which it beat Ducati to second in the manufacturers' standings, although it still only managed to win two races - both taken by Maverick Vinales - and its riders lagged behind Honda's runaway champion Marc Marquez.
Looking ahead to the 2020 season, Sumi said in an exclusive interview with Motorsport.com that it would be focussing on allowing its riders to be able to fight more easily in a race situation rather than seeking gains purely on laptime.
"Winning a race by escaping at the front, it’s only one way to do so," said Sumi. "But if the ideal line is disrupted by the rider in front, the speed cannot be shown.
"In other words, it’s hard for the riders to fight. That’s where we are still missing.
"We have to work to regain our strength in the races. We are working on that. Of course, the engine is a big place [for development].
"To beat your rivals on top speed, this is what Yamaha did not have in the past.
"I think the philosophy of the manufacturer appears in the way you try and get more speed, either just by increasing horsepower or improving the total balance of the package."
Fabio Quartararo, Petronas Yamaha SRT
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