McLaren CEO Zak Brown said the changes made to the operational side of the company's Formula One team were ultimately enough to convince Daniel Ricciardo to join for 2021.
McLaren came close to signing Ricciardo for 2019, but the Australian driver chose to sign for Renault instead. That decision was made when Renault was comfortably best of the rest and McLaren was struggling.
In the time since, McLaren has overtaken Renault, finishing ahead of the team which supplies its engines in 2019. Last year the team signed highly-rated technical director James Key from Toro Rosso and added Andreas Seidl, a key part of Porsche's domination of World Endurance Championship in the last decade, as team boss.
Brown believes those changes were fundamental.
When asked by the Australian Grand Prix podcast, In The Fast Lane, what the difference was between then and now, Brown said: "A couple of years ago we were coming off a horrific season, one of our worst in McLaren history. Really all I could do at that point was promise, or make claims, to Daniel on what my intentions were.
"But at that point it was just words -- I'm going to get a great team principal, I'm going to get a great technical director, we're going to get the resources we need, we're going to invest in CapEx. It was a lot of promises.
"I think, understandingly, he went 'it all sounds good, but you are coming off one of one of the worst seasons in McLaren's history'. Ultimately it didn't get him over the line for those reasons.
"Now instead of saying 'I'm going to get a great team principal' I can say 'I got Andreas Seidl', who's making a huge difference in the team. 'I'm going to get a great technical director', I got one in James Key.
"I think a year on he was able to see I put my money where my mouth is, so to speak, and the results were coming."
Ricciardo is one of a number of drivers switching F1 teams next year. Sebastian Vettel is leaving Ferrari for the Racing Point team ahead of its Aston Martin rebrand. Vettel is being replaced by McLaren's Carlos Sainz, whose place is being taken by Ricciardo.
Ricciardo's Renault seat is being taken by the returning Fernando Alonso, who has been on an extended sabbatical since stepping away from F1 at the end of 2018.