Bingo geohash achievement
In a traditional game of mostly chance called Bingo, players place tokens in a five by five grid according to numbers drawn by a caller. When a player has five tokens arranged in a straight line, vertically, horizontally or diagonally, he or she calls out "Bingo!" If the tokens are verified correct, that player wins the game. Each bingo card is unique, so the same set of called numbers will not necessarily be on everyone's card, and even if they are, may not be in a straight line. Traditionally the centre square on a bingo card is a "free square." It has no number on it, and the player may cover it with a token as soon as the game starts, so that technically a Bingo could be scored with only four numbers. There is a small element of skill in the game, because players have to be alert to the numbers called, locate them correctly on the card, and only the first person to call "Bingo!" wins a prize.
In the geohashing version, the caller is The Algorithm, the bingo card is the terrain you have to work with, the free square is your home graticule, and the difficulty of placing the chips is the challenge.
Claim this achievement if you successfully geohash five different graticules in a straight line. This is meant as an alternative to the Minesweeper achievement for those who live on a coastline and have no kingdom to offer for a boat. In the tradition of bingo, your home graticule is considered a free space (a space where it is considered as if you have successfully geohashed there, even if you haven't), which may be helpful for residents of Kekerengu, New Zealand. There is no strict definition of your 'home graticule,' but the free square concept is not present to allow you to take any group of four aligned graticules with a gap in it and call it a bingo. It is expected that only geohashers with oddly difficult home graticules will require the free square, but the concept is retained in the Bingo tradition.
 Completing the Card Geohash Achievement
An extension of this achievement is to "complete the card", which is to reach geohashes in all 25 of a 5x5 grid of graticules.
The cumulative proof of five aligned graticules geohashed. The straight line nature of the achievement can be easily shown from their numerical coordinates, although it may get a little awkward for bingoes crossing a pole.
| wmcduff earned the Bingo geohash achievement
 Winners in Waiting
- Ekorren got a west-east line of six between 48,7 and 48,12, another west-east line of five between 47,7 and 47,11, and a diagonal line of six between 47,8 and 52,13.