The weather can affect the outcome of a baseball game, with a 1 degree Celsius increase in the daily high temperature on the day of a game played in a stadium without a dome increasing the number of home runs by nearly 2%. This is based on the Parcel theory, where warm air rises due to its lower density than cooler air. Higher temperatures mean lower air density, which means less drag for curveballs and sliders, and for fastballs, this means the ball travels faster due to less drag. However, lower temperatures have higher air density which increases drag, which increases the “Magnus effect” which affects the curve of a ball and its trajectory. Wind plays a significant role in both pitched and batted balls, with headwind increasing the pitch's velocity and aiding pitchers and hitters alike. Major League Baseball has started using Weather Analytics technology to measure how weather affects the outcomes of games.