White will win if he plays perfectly: this is mathematically assured because white has an advantage of nine points. The only way for white to lose or to draw is by extreme error. The article assumes a perfect game, so I too assume that white will play a perfect game.
> Let me remind you that each ply has a branching factor of about 20, which means each move has a branching factor of several hundred. In most positions you'd be lucky to be able to calculate even one or two forced exchanges, let alone all the way to the end of the game.
As I recall, Deep Blue was calculating at a depth of more than eight moves...
> The Deep Blue chess computer which defeated Kasparov in 1997 would typically search to a depth of between six and eight moves to a maximum of twenty or even more moves in some situations. -- http://en.wikipedia.org/wiki/Deep_Blue_(chess_computer)
I find it difficult to believe that this wouldn't have improved or could not be improved upon, since this was based on the technology available in 1997. It's safe to say we've made progress since then.
While you may not be able to calculate an entire game, you could certainly calculate all the exchanges required to reach a properly winnable and calculable endgame. This is pretty damn close to being able to calculate a whole game...and you're assured victory.
As I said, once you get to a point of two kings and a queen, it's trivial.