One of Bill James’ cooler stats (no pun intended) is his Hot Teams and Batters system, which measures how hot a player or team is right now. Bill developed a scale that converts a player or team’s recent performance into a temperature in Fahrenheit. A team or player with a temperature of 100 degrees is really hot while a team or player with a temperature of 40 degrees is really cold, with room temperature of 72 being the norm.

On Bill James Online, you can actually see which teams and batters were hottest on each day of the season. Today—June 26, 2013—the hottest team in baseball is the Pittsburgh Pirates.

Meanwhile, exactly one month ago, the hottest team in baseball was...also the Pittsburgh Pirates!

You may not have realized how great the Pirates have been this season, in part because they’re being overshadowed by division rival St. Louis. However, while the Cardinals have the best record in baseball at 48-29, the Pirates are just one game back at 47-30 and have the second-best record in baseball. A big part of the Pirates’ success this season has been their defense. As a team, the Pirates have 27 Defensive Runs Saved, the third-most in baseball. In addition, they lead baseball with 255 defensive shifts on balls in play this season, good for five Shift Runs Saved.

The coldest team in baseball right now? The San Francisco Giants at 48 degrees.

As for individuals, the hottest hitters today are led by Jason Kipnis, who has reached base in 14 of his last 19 plate appearances, and Rickie Weeks, who went 3-4 with two home runs on Tuesday.