The BBC’s Andrew Benson mentions a topic I’ve touched on in his post-Singapore blog: those people who believe that Jenson Button won’t deserve to win the Formula 1 championship unless he wins another race.

It’s stupid, of course. It is a curious championship this year and no mistake, but that shouldn’t devalue the excellent job that Button and the Brawn GP team have done this year so far.

It got me looking back at past years, and how the title-winning driver got there. None of the last 15 seasons look remotely like this one – but you already knew that. There are similarities, though, particularly recently.

The first point is that Button has already won at least as many races as the last two champions: beating Lewis Hamilton‘s five in 2008 when he was fighting tooth and nail with Felipe Massa, and equalling Kimi Raikkonen‘s six in 2007 when he took the title by stealth from Hamilton and Alonso.

But it’s not really the number of wins that people have a problem with: it’s that those wins all came at the start of the season. Dry spells are not uncommon, though.

Button has now gone seven races without standing on the top step of the podium, but Fernando Alonso did the same in the second half of his successful 2006 championship campaign. Hamilton and Raikkonen both went six races without a win in their championship years, as did Alonso in 2005.

It’s worth looking at 2003, too. Ferrari, McLaren and Williams were all competitive, and although Michael Schumacher took the title, he did it with only six wins and two other podium finishes – exactly what Button has at this point. The difference is that this year teams have floated in and out of competitiveness, whereas the 2003 season was more consistent.

So although this season is unique, a lot of what we’re seeing is not without precedent.

It would be nice if Button could silence his critics with a strong last three races, picking up another win and the championship. But remember, we might yet find ourselves at the end of the year analysing whether Rubens Barrichello or Sebastian Vettel deserved to win the 2009 title.