batting practice balls come from the pool of balls discarded from the official game. (not included)
spring training balls wouildn't be counted because they are not part of the MLB season, they are counted as property of team. (not included)
promo balls shouldn't be included because typically they aren't mudded for play.
Home teams must have 90 balls on hand prior to each game, so how anyone reasonably propose teams use 200+ balls in a game? If that were the case, wouldn't MLB rules require more balls be prepared before each game?
The average lifespan of a baseball in a typical game is five pitches so, assuming the teams combine to throw 300 pitches in a game, that comes out to about 60 balls per game.
Multiply that by 2,430 games and that comes to 145,000 balls per season.
I'm going to estimate that a major league game averages about 150 pitches per team, and obviously, you won't have more than one ball per pitch used. I'm even going to estimate that each ball lasts approximately 3 pitches, so if 100 per game are used, then based on the 2430 regular season games that are played, you're looking at about 240-250,000 baseballs.
There are 30 teams in the MLB and each one hosts 81 home games per season for a total of 2430 games, counting only the regular season.
There are about 60 to 90 baseballs used in each game, which works out to somewhere between 145,000 to 218,000 balls throughout the season.
figure maybe 250,000 baseballs including preseason and playoffs. Remember that practice balls are just used game balls.
250k baseballs might seem like a lot, but consider that against the fact that Apple sold about 33,800,000 (33.8 million) iPhones in a 3 month period (4th quarter 2013). So 250,000 baseballs really isn't that much.
I saw previous answers to similar to this question. They are way way off. Consider everytime a baseball touches the ground (dirt) especially pitched balls it is tossed out. Then there are foul balls, balls thrown into the stands (foul balls, third out in an inning, etc.), home runs, and so on. A conservative estimate has to be like 250-300 a game. Just count how many are used even in a couple innings, you'd be amazed. That's well over 750,000 in the regular season. In addition, there are the playoffs, World Series, spring training, etc. And lets not forget batting practice, promotional balls and the like. Does MLB have a "ballpark" number?
