the best wood in your bag?

"With golf season upon us once again, we are reminded that the best wood in your bag is the pencil, preferably with an eraser on one end! As the old saying goes ..."

(from http://www.baltimoreview.com/dean12.htm)

Well, I guess "the best wood in your bag is the pencil" is an old saying in English. But what does it mean?

Lazarakis,
I think it means that the only thing that is usefull for you on that moment is with you,just search ,will find it.
that's my idea if you find better plz inform me .I really want to know the right meaning.
Goodluck....

A wood is type of a golf club, a wooden one, that a golfer plays with and carries around in his bag. I think it's considered the most important club in golf because the largest wood (there's a range of them) can hit the ball the furthest. So the passage is comparing the importance of a pencil, which is also wooden, to a golfer's livelihood: his woods.

It's not an old saying or a metaphor, it's just short for a wooden club, as the guest said. There are also metal clubs called "irons", usually numbered -- "Get me my five-iron!"

"With golf season upon us once again, we are reminded that the best wood in your bag is the pencil, preferably with an eraser on one end! As the old saying goes ..."

Another explanation:
Although the golfer can improve his/her game with a good club (wood), he/she can have a better game with a wooden pencil (with an eraser) because the golfer can simply change his scores with the pencil without needing to improving his game (aka cheating).

I guess it's a golfer's joke.