 Every once in a while a baseball announcer will say that a team has turned a 643 double play, in which case you might be wondering where those numbers came from and what are they referring to. Each player on a baseball team has a number on the back of their jersey, but they are more commonly referred to by the number of their position that is used when fans keep score of a baseball game. Unlike many sports, baseball has lots of stopping and starting which allows anybody who wants to to record each thing that happens in a game, but writing ground out to the shortstop would take up too much space, so instead they developed a shorthand way of writing things in which each position was assigned a number. So the pitcher is one, the catcher is two. In the infield it goes right to left, kind of. So the first baseman is three, the second baseman is four, the third baseman is five, and then back to the shortstop who is six. Then in the outfield it is left to right. So the left fielder is seven, the center fielder is eight, and then the right fielder is nine. So rather than writing ground out to the shortstop we could just write six to three, or perhaps in the case of a double play a six for three, meaning that the ground ball went from the shortstop who threw it to the second baseman who touched second and then finally threw it to the first baseman. There's a lot more to keep in score than that, but knowing the positional numbers will leave you a lot less confused at the ballpark.