Microsoft hasn’t shared Xbox One sales figures for more than a year, but an unverified report emerged last week claiming the console’s install base was somewhere around 18 million.

That’s half the nearly 36 million PlayStation 4 consoles Sony last week reported it has sold.

The Xbox sales claim was made by tech journalist Mary Jo Foley on the Windows Weekly podcast at around the nine minute mark, with Foley crediting an anonymous source with giving her the info.

"I can tell you what one source told me and I can't verify this," she said, so take the figure with an appropriately-sized grain of salt.

Microsoft did report Xbox One sales figures for the first few months of its life, but once it was clear Sony’s PlayStation 4 was in the lead, the company became very tight-lipped. The last official sales figure for the console was 10 million in late 2014, and after that, Microsoft bundled together Xbox 360 and Xbox One sales, before dropping the numbers completely.

The Xbox One may seem like it’s lagging, but assuming the rumoured figure is close to accurate, it has taken 26 months to reach 18m, while the Xbox 360 took 30 months to reach 19m. So, Microsoft's Xbox One may even be ahead of its most successful console to date, which ain't so bad.

Sony isn't shy at all about its sales figures, and the latest is that over the holiday period (11/22/2015 – 1/2/2016), it sold 5.7m PlayStation 4 consoles.

According to Wedbush Securities research analyst Michael Pachter, there is nothing Microsoft can do to close the gap.

Pointing out that the PlayStation 2 sold 170 million units while Microsoft’s best-selling console, the Xbox 360, sold 80 million units in its lifetime, Pachter said Sony had the familiarity advantage from the get-go.

“We should start every console cycle assuming Sony’s going to outsell Microsoft 2 to 1, because they have twice as many people who know what their console is,” he said on the latest episode of the Pachter Factor.