noun
100 yen per 1,000 points (mahjong parlor rate)
A mahjong parlor term for the rate at which game points are converted to money; specifically, 100 yen for every 1,000 points. Used when settling scores after a game.
この雀荘は点ピンだから、千点で百円の計算になる。
This mahjong parlor uses the tenpin rate, so it's 100 yen per 1,000 points.
ピン here is an abbreviation of 'pin' from 'one pin' (one yen per 10 points), indicating the base unit of the rate.
Compound of 点 (ten, 'points') and ピン (pin), an abbreviation of 'one pin' (1 yen per 10 points), referring to the rate of 100 yen per 1,000 points. The exact origin of 'pin' is uncertain, but it is used in mahjong parlance for monetary rates.