They count from right to left. The 1-board is the first board from the right gutter. The 10-board is where the second arrow (on the right) is located. The arrows, by the way, are 5 boards apart, so the third arrow is the 15-board.
This flips for lefties. If you're a lefty, the 1-board is the first board from the left gutter.
There are 39 boards, arrows every five. Some people might talk about 10L or 10R to avoid flipping the numbers for righty/lefty, but most find it easier to just number them from 1 to 39. The 20th board is the center one, the fourth arrow. If someone says they're playing the 10-board or swinging it 17 to 5, you can know what they're doing whether they're right-handed or left-handed, it's the same thing.
When they do say they're swinging it 17 to 5, that means the ball crosses the 17th board (between the third and fourth arrows) at the arrows, and the breakpoint, where the ball really changes direction is at the 5-board, around 40-45 feet downlane.
SH
Edited on 4/6/2006 12:19 PM